Initial commit: Brass & Sigil monorepo

Self-hosted Minecraft modpack distribution + administration system.

- launcher/  Avalonia 12 desktop client; single-file win-x64 publish.
             Microsoft auth via XboxAuthNet, manifest+SHA-1 mod sync,
             portable install path, sidecar settings.
- server/    brass-sigil-server daemon (.NET 8, linux-x64). Wraps the
             MC subprocess, embedded Kestrel admin panel with cookie
             auth + rate limiting, RCON bridge, scheduled backups,
             BlueMap CLI integration with player markers + skin proxy,
             friend-side whitelist request flow, world wipe with seed
             selection (keep current / random / custom).
- pack/      pack.lock.json (Modrinth + manual CurseForge entries),
             data-only tweak source under tweaks/, build outputs in
             overrides/ (gitignored).
- scripts/   Build-Pack / Build-Tweaks / Update-Pack / Check-Updates
             plus Deploy-Brass.ps1 unified one-shot deploy with
             version-bump pre-flight and daemon-state detection.

.gitignore

@@ -0,0 +1,62 @@
+# ─── .NET build outputs ───────────────────────────────────────────────────
+bin/
+obj/
+[Dd]ebug/
+[Dd]ebugPublic/
+[Rr]elease/
+[Rr]eleases/
+x64/
+x86/
+[Ll]og/
+[Ll]ogs/
+*.pdb
+*.user
+*.suo
+*.userosscache
+*.sln.docstates
+
+# ─── IDE state ────────────────────────────────────────────────────────────
+.vs/
+.vscode/
+.idea/
+*.sln.iml
+
+# ─── NuGet / package caches ───────────────────────────────────────────────
+*.nupkg
+*.snupkg
+.nuget/
+packages/
+project.lock.json
+project.fragment.lock.json
+artifacts/
+
+# ─── Build / publish output (every project) ───────────────────────────────
+publish/
+
+# ─── Misc OS junk ─────────────────────────────────────────────────────────
+*.swp
+.DS_Store
+Thumbs.db
+
+# ─── Local secrets / runtime config (track template, ignore real values) ─
+launcher/launcher-config.json
+server/deploy/server-config.json
+scripts/deploy.config.ps1
+
+# ─── Local AI assistant artifacts (Claude, Cursor, Copilot) ───────────────
+# Kept out of the public repo so collaborators aren't surprised by tool-
+# specific orientation files. Local copies stay usable in the working tree.
+CLAUDE.md
+.claude/
+.cursor/
+.cursorrules
+.aider*
+.github/copilot*
+
+# ─── Build artifacts that get regenerated ─────────────────────────────────
+# Tweak jars rebuilt by scripts/Build-Tweaks.ps1
+pack/overrides/
+# manifest.json regenerated by scripts/Build-Pack.ps1 -- produced at scripts/
+# (default OutputPath) and copied to the deploy share by Deploy-Brass.ps1
+scripts/manifest.json
+pack/manifest.json

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Matt Sijbers
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,68 @@
+# Brass & Sigil
+
+Self-hosted Minecraft modpack distribution + administration system.
+Three components, one repo:
+
+```
+brass-and-sigil/
+├── launcher/   ← Avalonia desktop client (Windows .NET 8)
+│                  Auths with Microsoft, syncs the modpack, launches the game.
+├── server/     ← brass-sigil-server daemon (Linux .NET 8)
+│                  Wraps the MC subprocess, exposes the admin web panel,
+│                  syncs mods, runs backups + BlueMap, handles whitelist.
+├── pack/       ← Modpack content
+│   ├── pack.lock.json    Source of truth for mod versions / URLs / hashes
+│   ├── tweaks/           Hand-written data-only tweak source
+│   └── overrides/        Build output / hand-placed local files (gitignored)
+├── scripts/    ← Build + deploy entry points (run from repo root)
+│   ├── Update-Pack.ps1     Refresh pack.lock.json from Modrinth/CurseForge
+│   ├── Check-Updates.ps1   Non-mutating "what's new?" report
+│   ├── Build-Tweaks.ps1    Compile tweaks/ into pack/overrides/mods/*.jar
+│   ├── Build-Pack.ps1      Generate manifest.json from the lockfile
+│   └── Deploy-Brass.ps1    One-shot build + deploy everything
+└── docs/       ← Operational notes, deploy runbook, schema docs
+```
+
+## Quick start
+
+```powershell
+# Pull dependencies, copy and edit the deploy profile
+git clone <remote> brass-and-sigil
+cd brass-and-sigil
+Copy-Item scripts\deploy.config.template.ps1 scripts\deploy.config.ps1
+notepad scripts\deploy.config.ps1   # fill in deploy share, SSH host, etc.
+
+# Build + deploy everything in one go
+.\scripts\Deploy-Brass.ps1
+```
+
+`deploy.config.ps1` is gitignored -- local values never get committed.
+
+## Component reference
+
+| Component | What it does | Technology |
+|-----------|--------------|------------|
+| `launcher/` | Friend-distributed client. Auths with Microsoft via WebView2 + XboxAuthNet, downloads mods, launches Minecraft. Single self-contained `.exe` published from `publish/`. | Avalonia 12 + CmlLib.Core |
+| `server/` | Daemon running alongside the MC process on Linux. Hosts a Kestrel web panel for admin (cookie-auth, rate-limited), bridges RCON, runs scheduled backups + BlueMap renders, handles whitelist requests. | ASP.NET Core minimal APIs |
+| `pack/` | Lockfile-driven modpack content. `pack.lock.json` resolves mod slug → URL+SHA-1; `Build-Pack.ps1` walks it and produces `manifest.json` for the launcher and the server-tool to consume. | PowerShell tooling |
+
+## Workflow
+
+1. **Bump mod versions:** `.\scripts\Update-Pack.ps1` (queries Modrinth + manual CurseForge entries).
+2. **Sanity-check:** `.\scripts\Check-Updates.ps1` for a non-mutating availability report.
+3. **Edit tweaks** under `pack/tweaks/<name>/` if you're changing recipes / loot / etc.
+4. **Deploy:** `.\scripts\Deploy-Brass.ps1` -- builds launcher + server, regenerates manifest, mirrors everything to the deploy share, scp's the server binary.
+
+## Secrets / config files
+
+| File | Tracked? | Notes |
+|------|----------|-------|
+| `launcher/launcher-config.template.json` | ✓ | Empty placeholders, public-safe |
+| `launcher/launcher-config.json` | ✗ | Local override; merged into the published exe at build time if present |
+| `server/deploy/server-config.example.json` | ✓ | Template; rename to `server-config.json` on the server with real values |
+| `server/deploy/server-config.json` | ✗ | Production config; lives on the server only |
+| `scripts/deploy.config.ps1` | ✗ | Local deploy profile (paths, SSH host, share location) |
+
+## License
+
+See `LICENSE`.

launcher/App.axaml

@@ -0,0 +1,9 @@
+<Application xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             x:Class="ModpackLauncher.App"
+             RequestedThemeVariant="Dark">
+
+    <Application.Styles>
+        <FluentTheme />
+    </Application.Styles>
+</Application>

launcher/App.axaml.cs

@@ -0,0 +1,23 @@
+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Markup.Xaml;
+
+namespace ModpackLauncher;
+
+public partial class App : Application
+{
+    public override void Initialize()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    public override void OnFrameworkInitializationCompleted()
+    {
+        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            desktop.MainWindow = new MainWindow();
+        }
+
+        base.OnFrameworkInitializationCompleted();
+    }
+}

launcher/Assets/build-icon.ps1

@@ -0,0 +1,98 @@
+#requires -Version 5
+# One-shot helper: produces a multi-resolution icon.ico from icon.png.
+# Run only when the source icon changes; commit the resulting icon.ico.
+
+Add-Type -AssemblyName System.Drawing
+Add-Type -AssemblyName PresentationCore
+Add-Type -AssemblyName WindowsBase
+
+$here    = Split-Path -Parent $MyInvocation.MyCommand.Path
+$srcPath = Join-Path $here 'icon.png'
+$icoPath = Join-Path $here 'icon.ico'
+
+if (-not (Test-Path $srcPath)) { throw "icon.png not found at $srcPath" }
+
+# Detect if the file is actually a different format renamed to .png (e.g. WebP from AI tools).
+# If so, transcode via WPF's WIC pipeline to a real PNG before feeding GDI+.
+$head = [System.IO.File]::ReadAllBytes($srcPath)[0..3]
+$isPng = $head[0] -eq 0x89 -and $head[1] -eq 0x50 -and $head[2] -eq 0x4E -and $head[3] -eq 0x47
+if (-not $isPng) {
+    Write-Host "Source file is not a PNG (likely WebP from AI tool). Transcoding via WIC..."
+    $bytes  = [System.IO.File]::ReadAllBytes($srcPath)
+    $stream = New-Object System.IO.MemoryStream(,$bytes)
+    $decoder = [System.Windows.Media.Imaging.BitmapDecoder]::Create(
+        $stream,
+        [System.Windows.Media.Imaging.BitmapCreateOptions]::PreservePixelFormat,
+        [System.Windows.Media.Imaging.BitmapCacheOption]::OnLoad)
+    $frame = $decoder.Frames[0]
+    # Force BGRA32 so GDI+ can later handle it cleanly with alpha
+    $converted = New-Object System.Windows.Media.Imaging.FormatConvertedBitmap(
+        $frame,
+        [System.Windows.Media.PixelFormats]::Bgra32,
+        $null,
+        0)
+    $encoder = New-Object System.Windows.Media.Imaging.PngBitmapEncoder
+    $encoder.Frames.Add([System.Windows.Media.Imaging.BitmapFrame]::Create($converted))
+    $outStream = New-Object System.IO.MemoryStream
+    $encoder.Save($outStream)
+    [System.IO.File]::WriteAllBytes($srcPath, $outStream.ToArray())
+    $outStream.Dispose()
+    $stream.Dispose()
+    Write-Host "Transcoded to real PNG ($($outStream.Length) bytes)."
+}
+
+$sizes = 16, 32, 48, 64, 128, 256
+$src   = [System.Drawing.Image]::FromFile($srcPath)
+$frames = @{}
+
+foreach ($size in $sizes) {
+    $bmp = New-Object System.Drawing.Bitmap $size, $size, ([System.Drawing.Imaging.PixelFormat]::Format32bppArgb)
+    $g   = [System.Drawing.Graphics]::FromImage($bmp)
+    $g.InterpolationMode  = [System.Drawing.Drawing2D.InterpolationMode]::HighQualityBicubic
+    $g.SmoothingMode      = [System.Drawing.Drawing2D.SmoothingMode]::HighQuality
+    $g.PixelOffsetMode    = [System.Drawing.Drawing2D.PixelOffsetMode]::HighQuality
+    $g.CompositingQuality = [System.Drawing.Drawing2D.CompositingQuality]::HighQuality
+    $g.DrawImage($src, 0, 0, $size, $size)
+    $g.Dispose()
+
+    $ms = New-Object System.IO.MemoryStream
+    $bmp.Save($ms, [System.Drawing.Imaging.ImageFormat]::Png)
+    $frames[$size] = $ms.ToArray()
+    $bmp.Dispose()
+    $ms.Dispose()
+}
+
+$out = New-Object System.IO.MemoryStream
+$bw  = New-Object System.IO.BinaryWriter($out)
+
+# ICONDIR header
+$bw.Write([UInt16]0)
+$bw.Write([UInt16]1)
+$bw.Write([UInt16]$sizes.Count)
+
+$dataOffset = 6 + (16 * $sizes.Count)
+foreach ($size in $sizes) {
+    $bytes = $frames[$size]
+    $w = if ($size -ge 256) { [byte]0 } else { [byte]$size }
+    $h = if ($size -ge 256) { [byte]0 } else { [byte]$size }
+    $bw.Write([byte]$w)
+    $bw.Write([byte]$h)
+    $bw.Write([byte]0)
+    $bw.Write([byte]0)
+    $bw.Write([UInt16]1)
+    $bw.Write([UInt16]32)
+    $bw.Write([UInt32]$bytes.Length)
+    $bw.Write([UInt32]$dataOffset)
+    $dataOffset += $bytes.Length
+}
+
+foreach ($size in $sizes) {
+    $bw.Write($frames[$size])
+}
+
+[System.IO.File]::WriteAllBytes($icoPath, $out.ToArray())
+$bw.Dispose()
+$out.Dispose()
+$src.Dispose()
+
+"Wrote: $icoPath ($((Get-Item $icoPath).Length) bytes, $($sizes.Count) sizes)"

launcher/Assets/build-noise.ps1

@@ -0,0 +1,43 @@
+#requires -Version 5
+# One-shot helper: generates a subtle warm-tinted tileable noise texture
+# at Assets/noise.png. Run only when you want to regenerate the texture.
+
+Add-Type -AssemblyName System.Drawing
+
+$here    = Split-Path -Parent $MyInvocation.MyCommand.Path
+$outPath = Join-Path $here 'noise.png'
+
+$size = 128
+$bmp  = New-Object System.Drawing.Bitmap $size, $size, ([System.Drawing.Imaging.PixelFormat]::Format32bppArgb)
+$rng  = New-Object System.Random 1337
+
+# Lock bits for fast pixel access
+$rect = New-Object System.Drawing.Rectangle 0, 0, $size, $size
+$data = $bmp.LockBits($rect, [System.Drawing.Imaging.ImageLockMode]::WriteOnly,
+    [System.Drawing.Imaging.PixelFormat]::Format32bppArgb)
+$bytes = New-Object byte[] ($data.Stride * $size)
+
+function Clamp([double]$v, [double]$lo, [double]$hi) {
+    if ($v -lt $lo) { return $lo }
+    if ($v -gt $hi) { return $hi }
+    return $v
+}
+
+for ($y = 0; $y -lt $size; $y++) {
+    for ($x = 0; $x -lt $size; $x++) {
+        $offset = ($y * $data.Stride) + ($x * 4)
+        # Cool dark grain to overlay on a navy backdrop -- gives subtle metallic noise
+        $n = ($rng.NextDouble() - 0.5) * 2.0  # -1.0 .. 1.0
+        $bytes[$offset]     = [byte](Clamp (110 + ($n * 50)) 0 255)   # B
+        $bytes[$offset + 1] = [byte](Clamp (105 + ($n * 50)) 0 255)   # G
+        $bytes[$offset + 2] = [byte](Clamp (95  + ($n * 50)) 0 255)   # R
+        $bytes[$offset + 3] = 28                                       # A (~11%)
+    }
+}
+
+[System.Runtime.InteropServices.Marshal]::Copy($bytes, 0, $data.Scan0, $bytes.Length)
+$bmp.UnlockBits($data)
+$bmp.Save($outPath, [System.Drawing.Imaging.ImageFormat]::Png)
+$bmp.Dispose()
+
+"Wrote: $outPath ($((Get-Item $outPath).Length) bytes, ${size}x${size})"

launcher/MainWindow.axaml

@@ -0,0 +1,395 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        mc:Ignorable="d" d:DesignWidth="900" d:DesignHeight="600"
+        x:Class="ModpackLauncher.MainWindow"
+        Title="Modpack Launcher"
+        Width="900" Height="640"
+        MinWidth="720" MinHeight="540"
+        Background="Transparent"
+        TransparencyLevelHint="Transparent"
+        WindowDecorations="None"
+        Icon="/Assets/icon.png"
+        WindowStartupLocation="CenterScreen">
+
+    <Window.Resources>
+        <!-- Palette: dark navy base + brass trim + cyan magic accent -->
+
+        <!-- Brass gradient (lit from top, polished) -->
+        <LinearGradientBrush x:Key="BrassTrim" StartPoint="0%,0%" EndPoint="0%,100%">
+            <GradientStop Offset="0"   Color="#F5D88A" />
+            <GradientStop Offset="0.35" Color="#E8B95C" />
+            <GradientStop Offset="0.65" Color="#A37A2E" />
+            <GradientStop Offset="1"   Color="#5C4519" />
+        </LinearGradientBrush>
+        <LinearGradientBrush x:Key="BrassFill" StartPoint="0%,0%" EndPoint="0%,100%">
+            <GradientStop Offset="0"   Color="#F5D88A" />
+            <GradientStop Offset="0.5" Color="#D4A24C" />
+            <GradientStop Offset="1"   Color="#8C6829" />
+        </LinearGradientBrush>
+        <LinearGradientBrush x:Key="BrassFillHover" StartPoint="0%,0%" EndPoint="0%,100%">
+            <GradientStop Offset="0"   Color="#FBE3A0" />
+            <GradientStop Offset="0.5" Color="#E8B95C" />
+            <GradientStop Offset="1"   Color="#A37A2E" />
+        </LinearGradientBrush>
+
+        <!-- Rivet (radial gradient, lit from upper-left) -->
+        <RadialGradientBrush x:Key="RivetFill" Center="35%,35%" GradientOrigin="35%,35%" RadiusX="0.55" RadiusY="0.55">
+            <GradientStop Offset="0"   Color="#F8DC95" />
+            <GradientStop Offset="0.5" Color="#C99843" />
+            <GradientStop Offset="1"   Color="#3F2E10" />
+        </RadialGradientBrush>
+
+        <!-- Card fill (deep navy gradient) -->
+        <LinearGradientBrush x:Key="CardFill" StartPoint="0%,0%" EndPoint="0%,100%">
+            <GradientStop Offset="0" Color="#13192A" />
+            <GradientStop Offset="1" Color="#0A0F1A" />
+        </LinearGradientBrush>
+
+        <!-- Title bar metallic -->
+        <LinearGradientBrush x:Key="TitleBarFill" StartPoint="0%,0%" EndPoint="0%,100%">
+            <GradientStop Offset="0" Color="#0F1626" />
+            <GradientStop Offset="1" Color="#070B16" />
+        </LinearGradientBrush>
+
+        <!-- Magic cyan glow (radial) -->
+        <RadialGradientBrush x:Key="MagicGlow" Center="50%,50%" GradientOrigin="50%,50%" RadiusX="0.8" RadiusY="0.8">
+            <GradientStop Offset="0"   Color="#605DD4E8" />
+            <GradientStop Offset="0.5" Color="#205DD4E8" />
+            <GradientStop Offset="1"   Color="#005DD4E8" />
+        </RadialGradientBrush>
+
+        <!-- Tileable noise overlay -->
+        <ImageBrush x:Key="NoiseBrush" Source="/Assets/noise.png"
+                    TileMode="Tile" Stretch="None"
+                    DestinationRect="0,0,128,128" />
+    </Window.Resources>
+
+    <Window.Styles>
+        <!-- Reusable "brass panel" with metal trim + corner rivets -->
+        <Style Selector="ContentControl.brass-panel">
+            <Setter Property="Padding" Value="20" />
+            <Setter Property="Template">
+                <ControlTemplate>
+                    <Grid>
+                        <!-- Outer brass trim -->
+                        <Border BorderBrush="{StaticResource BrassTrim}" BorderThickness="2" CornerRadius="6"
+                                Background="{StaticResource CardFill}">
+                            <ContentPresenter Content="{TemplateBinding Content}"
+                                              Margin="{TemplateBinding Padding}" />
+                        </Border>
+                        <!-- Corner rivets -->
+                        <Ellipse Width="6" Height="6" HorizontalAlignment="Left"  VerticalAlignment="Top"
+                                 Margin="6" Fill="{StaticResource RivetFill}" />
+                        <Ellipse Width="6" Height="6" HorizontalAlignment="Right" VerticalAlignment="Top"
+                                 Margin="6" Fill="{StaticResource RivetFill}" />
+                        <Ellipse Width="6" Height="6" HorizontalAlignment="Left"  VerticalAlignment="Bottom"
+                                 Margin="6" Fill="{StaticResource RivetFill}" />
+                        <Ellipse Width="6" Height="6" HorizontalAlignment="Right" VerticalAlignment="Bottom"
+                                 Margin="6" Fill="{StaticResource RivetFill}" />
+                    </Grid>
+                </ControlTemplate>
+            </Setter>
+        </Style>
+
+        <!-- Primary button: brass gradient + cyan magic hover glow -->
+        <Style Selector="Button.primary">
+            <Setter Property="Background" Value="{StaticResource BrassFill}" />
+            <Setter Property="Foreground" Value="#1A140F" />
+            <Setter Property="Padding" Value="26 12" />
+            <Setter Property="FontSize" Value="16" />
+            <Setter Property="FontWeight" Value="Bold" />
+            <Setter Property="CornerRadius" Value="6" />
+            <Setter Property="BorderBrush" Value="#5C4519" />
+            <Setter Property="BorderThickness" Value="1" />
+        </Style>
+        <Style Selector="Button.primary:pointerover /template/ ContentPresenter">
+            <Setter Property="Background" Value="{StaticResource BrassFillHover}" />
+        </Style>
+        <Style Selector="Button.primary:disabled /template/ ContentPresenter">
+            <Setter Property="Background" Value="#3A2D1E" />
+            <Setter Property="Foreground" Value="#6B5F4A" />
+        </Style>
+
+        <!-- Secondary button -->
+        <Style Selector="Button.secondary">
+            <Setter Property="Background" Value="#1B233A" />
+            <Setter Property="Foreground" Value="#E8DFC8" />
+            <Setter Property="Padding" Value="14 8" />
+            <Setter Property="CornerRadius" Value="4" />
+            <Setter Property="BorderBrush" Value="#A37A2E" />
+            <Setter Property="BorderThickness" Value="1" />
+        </Style>
+        <Style Selector="Button.secondary:pointerover /template/ ContentPresenter">
+            <Setter Property="Background" Value="#26314D" />
+            <Setter Property="BorderBrush" Value="#E8B95C" />
+        </Style>
+
+        <Style Selector="TextBlock.h1">
+            <Setter Property="FontSize" Value="22" />
+            <Setter Property="FontWeight" Value="SemiBold" />
+            <Setter Property="Foreground" Value="#E8DFC8" />
+        </Style>
+        <Style Selector="TextBlock.muted">
+            <Setter Property="Foreground" Value="#7A8497" />
+            <Setter Property="FontSize" Value="13" />
+        </Style>
+
+        <!-- Brass progress bar -->
+        <Style Selector="ProgressBar.brass">
+            <Setter Property="Foreground" Value="{StaticResource BrassFill}" />
+            <Setter Property="Background" Value="#0A0F1A" />
+            <Setter Property="BorderBrush" Value="{StaticResource BrassTrim}" />
+            <Setter Property="BorderThickness" Value="1" />
+        </Style>
+
+        <!-- Custom title bar caption buttons -->
+        <Style Selector="Button.caption">
+            <Setter Property="Background" Value="Transparent" />
+            <Setter Property="Width" Value="46" />
+            <Setter Property="Height" Value="36" />
+            <Setter Property="CornerRadius" Value="0" />
+            <Setter Property="Padding" Value="0" />
+            <Setter Property="HorizontalContentAlignment" Value="Center" />
+            <Setter Property="VerticalContentAlignment" Value="Center" />
+        </Style>
+        <Style Selector="Button.caption:pointerover /template/ ContentPresenter">
+            <Setter Property="Background" Value="#1B233A" />
+        </Style>
+        <Style Selector="Button.caption Path">
+            <Setter Property="Stroke" Value="#A37A2E" />
+            <Setter Property="StrokeThickness" Value="1" />
+            <Setter Property="HorizontalAlignment" Value="Center" />
+            <Setter Property="VerticalAlignment" Value="Center" />
+        </Style>
+        <Style Selector="Button.caption:pointerover Path">
+            <Setter Property="Stroke" Value="#F5D88A" />
+        </Style>
+        <Style Selector="Button.caption-close">
+            <Setter Property="Background" Value="Transparent" />
+            <Setter Property="Width" Value="46" />
+            <Setter Property="Height" Value="36" />
+            <Setter Property="CornerRadius" Value="0" />
+            <Setter Property="Padding" Value="0" />
+            <Setter Property="HorizontalContentAlignment" Value="Center" />
+            <Setter Property="VerticalContentAlignment" Value="Center" />
+        </Style>
+        <Style Selector="Button.caption-close:pointerover /template/ ContentPresenter">
+            <Setter Property="Background" Value="#B94228" />
+        </Style>
+        <Style Selector="Button.caption-close Path">
+            <Setter Property="Stroke" Value="#A37A2E" />
+            <Setter Property="StrokeThickness" Value="1" />
+            <Setter Property="HorizontalAlignment" Value="Center" />
+            <Setter Property="VerticalAlignment" Value="Center" />
+        </Style>
+        <Style Selector="Button.caption-close:pointerover Path">
+            <Setter Property="Stroke" Value="#F5D88A" />
+        </Style>
+    </Window.Styles>
+
+    <!-- Outermost: main brass-bordered window + slide-out info panel (separate column, OUTSIDE the window) -->
+    <Grid>
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="*" />
+            <ColumnDefinition Width="Auto" />
+        </Grid.ColumnDefinitions>
+
+        <Border Grid.Column="0" Name="RootBorder" CornerRadius="10"
+                Background="{StaticResource BrassTrim}"
+                ClipToBounds="True">
+            <Border CornerRadius="8" Background="#0B1220" Margin="2" ClipToBounds="True">
+                <Panel Background="{StaticResource NoiseBrush}">
+                <Grid RowDefinitions="36,1,*">
+
+                    <!-- Title bar -->
+                    <Grid Grid.Row="0" Name="TitleBar" Background="{StaticResource TitleBarFill}"
+                          PointerPressed="OnTitleBarPressed">
+                        <Grid.ColumnDefinitions>
+                            <ColumnDefinition Width="*" />
+                            <ColumnDefinition Width="Auto" />
+                        </Grid.ColumnDefinitions>
+
+                        <!-- Magic glow halo behind icon + title text -->
+                        <Grid Grid.Column="0" Margin="10 0 0 0" VerticalAlignment="Center" IsHitTestVisible="False">
+                            <Ellipse Width="36" Height="36" HorizontalAlignment="Left"
+                                     Margin="-8 0 0 0" Fill="{StaticResource MagicGlow}" />
+                            <StackPanel Orientation="Horizontal" Spacing="10" VerticalAlignment="Center">
+                                <Image Source="/Assets/icon.png" Width="22" Height="22"
+                                       RenderOptions.BitmapInterpolationMode="HighQuality" />
+                                <TextBlock Name="TitleText" Text="Brass &amp; Sigil Launcher"
+                                           Foreground="#F5D88A" FontSize="12" FontWeight="SemiBold"
+                                           VerticalAlignment="Center" />
+                            </StackPanel>
+                        </Grid>
+
+                        <StackPanel Grid.Column="1" Orientation="Horizontal" VerticalAlignment="Stretch">
+                            <Button Classes="caption" Click="OnRefreshClick" ToolTip.Tip="Check for updates">
+                                <Path Width="11" Height="11"
+                                      Data="M 9,1.5 A 4,4 0 1 0 10.5,5 M 9,1.5 V 4 H 6.5" />
+                            </Button>
+                            <Button Classes="caption" Click="OnInfoClick" ToolTip.Tip="Pack info">
+                                <Path Width="11" Height="11"
+                                      Data="M 5.5,0.5 A 5,5 0 1 1 5.499,0.5 Z M 5.5,4 V 9 M 5.5,2 V 2.5" />
+                            </Button>
+                            <Button Classes="caption" Click="OnMinimizeClick" ToolTip.Tip="Minimize">
+                                <Path Width="10" Height="10" Data="M 0,5 H 10" />
+                            </Button>
+                            <Button Classes="caption-close" Click="OnCloseClick" ToolTip.Tip="Close">
+                                <Path Width="10" Height="10" Data="M 0,0 L 10,10 M 10,0 L 0,10" />
+                            </Button>
+                        </StackPanel>
+                    </Grid>
+
+                    <!-- Brass divider hairline (own row so hover backgrounds can't paint over it) -->
+                    <Border Grid.Row="1" Background="{StaticResource BrassTrim}" IsHitTestVisible="False" />
+
+                    <!-- Main content -->
+                    <Grid Grid.Row="2" RowDefinitions="Auto,Auto,*,Auto" Margin="14">
+
+                        <!-- Update-available banner (hidden until manifest reports a newer launcherVersion) -->
+                        <Border Name="UpdateBanner" Grid.Row="0" IsVisible="False"
+                                Background="#13192A" BorderBrush="#D4A24C" BorderThickness="1"
+                                CornerRadius="6" Padding="12 10" Margin="0 0 0 12">
+                            <Grid ColumnDefinitions="Auto,*,Auto" VerticalAlignment="Center">
+                                <TextBlock Grid.Column="0" Text="ⓘ" FontSize="16"
+                                           Foreground="#E8B95C" VerticalAlignment="Center" Margin="0 0 10 0" />
+                                <TextBlock Grid.Column="1" Name="UpdateBannerText" VerticalAlignment="Center"
+                                           Foreground="#E8DFC8" FontSize="13" TextWrapping="Wrap"
+                                           Text="A newer launcher is available." />
+                                <Button Grid.Column="2" Name="UpdateBannerDownloadButton"
+                                        Classes="secondary" Content="Download"
+                                        Click="OnUpdateBannerDownloadClick" />
+                            </Grid>
+                        </Border>
+
+                        <!-- Header card -->
+                        <ContentControl Grid.Row="1" Classes="brass-panel" Margin="0 0 0 14">
+                            <Grid ColumnDefinitions="*,Auto">
+                                <StackPanel Grid.Column="0" Orientation="Vertical" Spacing="4">
+                                    <TextBlock Name="PackNameText" Classes="h1" Text="Modpack" />
+                                    <TextBlock Name="PackVersionText" Classes="muted" Text="No pack synced yet" />
+                                </StackPanel>
+                                <StackPanel Grid.Column="1" Orientation="Horizontal" VerticalAlignment="Center" Spacing="10">
+                                    <TextBlock Name="UserText" Classes="muted" Text="Not signed in" VerticalAlignment="Center" />
+                                    <TextBlock Name="WhitelistStatusText" Classes="muted" Text="" IsVisible="False"
+                                               VerticalAlignment="Center" FontStyle="Italic" />
+                                    <Button Name="RequestAccessButton" Classes="secondary" Content="Request access"
+                                            Click="OnRequestAccessClick" IsVisible="False"
+                                            ToolTip.Tip="Send the server admin a request to whitelist your account." />
+                                    <Button Name="LoginButton" Classes="secondary" Content="Sign in" Click="OnLoginClick" />
+                                    <Button Name="LogoutButton" Classes="secondary" Content="Sign out"
+                                            Click="OnLogoutClick" IsVisible="False" />
+                                </StackPanel>
+                            </Grid>
+                        </ContentControl>
+
+                        <!-- Action + log -->
+                        <Grid Grid.Row="2" RowDefinitions="Auto,*">
+                            <ContentControl Grid.Row="0" Classes="brass-panel" Margin="0 0 0 14">
+                                <StackPanel Spacing="14">
+                                    <Grid ColumnDefinitions="*,Auto">
+                                        <StackPanel Grid.Column="0" VerticalAlignment="Center" Spacing="2">
+                                            <TextBlock Name="StatusText" Classes="h1" Text="Ready" />
+                                            <TextBlock Name="StatusSubtext" Classes="muted"
+                                                       Text="Click Play to sync the pack and launch Minecraft." />
+                                        </StackPanel>
+                                        <!-- Play button with subtle cyan glow halo behind -->
+                                        <Grid Grid.Column="1" Width="180" Height="48">
+                                            <Ellipse HorizontalAlignment="Center" VerticalAlignment="Center"
+                                                     Width="200" Height="80" Fill="{StaticResource MagicGlow}"
+                                                     Opacity="0.45" IsHitTestVisible="False" />
+                                            <Button Name="PlayButton" Classes="primary" Content="Play"
+                                                    HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
+                                                    Click="OnPlayClick" />
+                                        </Grid>
+                                    </Grid>
+                                    <ProgressBar Name="ProgressBar" Classes="brass" Height="8"
+                                                 Minimum="0" Maximum="100" Value="0" CornerRadius="4" />
+                                </StackPanel>
+                            </ContentControl>
+
+                            <ContentControl Grid.Row="1" Classes="brass-panel">
+                                <Grid RowDefinitions="Auto,*">
+                                    <Grid Grid.Row="0" ColumnDefinitions="*,Auto" Margin="0 0 0 8">
+                                        <TextBlock Grid.Column="0" Classes="h1" Text="Log" FontSize="14" />
+                                        <Button Grid.Column="1" Classes="secondary" Content="Open install folder"
+                                                Click="OnOpenFolderClick" />
+                                    </Grid>
+                                    <Border Grid.Row="1" Background="#070B16" CornerRadius="4" Padding="10"
+                                            BorderBrush="#1B233A" BorderThickness="1">
+                                        <ScrollViewer Name="LogScroll" VerticalScrollBarVisibility="Auto">
+                                            <TextBlock Name="LogText" FontFamily="Cascadia Mono, Consolas, monospace"
+                                                       FontSize="12" Foreground="#B7C0D6" TextWrapping="Wrap" />
+                                        </ScrollViewer>
+                                    </Border>
+                                </Grid>
+                            </ContentControl>
+                        </Grid>
+
+                        <!-- Footer / settings -->
+                        <ContentControl Grid.Row="3" Classes="brass-panel" Margin="0 14 0 0">
+                            <StackPanel Spacing="10">
+                                <!-- RAM allocation -->
+                                <Grid ColumnDefinitions="Auto,Auto,*,Auto">
+                                    <TextBlock Grid.Column="0" Text="RAM" VerticalAlignment="Center" Classes="muted" />
+                                    <NumericUpDown Grid.Column="1" Name="RamBox" Margin="10 0 10 0" Width="140"
+                                                   Minimum="2048" Maximum="65536" Increment="1024" FormatString="0" />
+                                    <TextBlock Grid.Column="2" Text="MB" VerticalAlignment="Center" Classes="muted" Margin="0 0 10 0" />
+                                    <TextBlock Grid.Column="3" Name="RamWarningText" VerticalAlignment="Center"
+                                               FontSize="11" TextWrapping="Wrap" />
+                                </Grid>
+                                <!-- Install location -->
+                                <Grid ColumnDefinitions="Auto,*,Auto">
+                                    <TextBlock Grid.Column="0" Text="Install location" VerticalAlignment="Center" Classes="muted" />
+                                    <TextBlock Grid.Column="1" Name="InstallDirText" VerticalAlignment="Center" Margin="10 0 10 0"
+                                               TextTrimming="CharacterEllipsis" Foreground="#B7C0D6" FontSize="12" />
+                                    <Button Grid.Column="2" Classes="secondary" Content="Change..." Click="OnChangeInstallDirClick" />
+                                </Grid>
+                                <TextBlock Foreground="#5C6478" FontSize="10" TextWrapping="Wrap" HorizontalAlignment="Center"
+                                           Text="NOT AN OFFICIAL MINECRAFT PRODUCT. NOT APPROVED BY OR ASSOCIATED WITH MOJANG OR MICROSOFT." />
+                            </StackPanel>
+                        </ContentControl>
+                    </Grid>
+
+                </Grid>
+                </Panel>
+            </Border>
+        </Border>
+
+        <!-- Slide-out container: starts at Width=0 so the Auto column contributes nothing.
+             InfoPanel inside has fixed Width=320; HorizontalAlignment=Right + ClipToBounds=True
+             on the container makes the panel "slide in" from the right as the container grows.
+             Window.Width is animated in lock-step with InfoPanelContainer.Width so the main
+             content (RootBorder, in the Star column) keeps its current width throughout.
+             Vertically: outer Grid is single-row (full window height) so this Border
+             stretches naturally; the inner ScrollViewer inherits it via its Auto,*
+             Grid row. No code-behind height management needed. -->
+        <Border Grid.Column="1" Name="InfoPanelContainer" Width="0"
+                ClipToBounds="True">
+            <Border Name="InfoPanel" HorizontalAlignment="Right" Width="320" Margin="14 0 0 0"
+                    CornerRadius="10" Background="{StaticResource BrassTrim}"
+                    ClipToBounds="True">
+                <Border CornerRadius="8" Background="#0F1622" Margin="2" ClipToBounds="True">
+                    <Grid RowDefinitions="Auto,*">
+                        <Grid Grid.Row="0" ColumnDefinitions="*,Auto" Margin="14 12 8 8">
+                            <TextBlock Grid.Column="0" Classes="h1" Text="Pack info" FontSize="14"
+                                       VerticalAlignment="Center" />
+                            <Button Grid.Column="1" Classes="caption" Click="OnInfoClick" ToolTip.Tip="Close"
+                                    Width="32" Height="28">
+                                <Path Width="9" Height="9" Data="M 0,0 L 9,9 M 9,0 L 0,9" />
+                            </Button>
+                        </Grid>
+                        <ScrollViewer Grid.Row="1" Name="InfoScrollViewer"
+                                      Padding="14 0 14 40"
+                                      VerticalScrollBarVisibility="Auto"
+                                      HorizontalScrollBarVisibility="Disabled">
+                            <StackPanel Name="InfoPanelContent" Spacing="14" Margin="0 0 0 8" />
+                        </ScrollViewer>
+                    </Grid>
+                </Border>
+            </Border>
+        </Border>
+    </Grid>
+</Window>

launcher/MainWindow.axaml.cs

@@ -0,0 +1,980 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Avalonia.Media;
+using Avalonia.Platform.Storage;
+using Avalonia.Threading;
+using CmlLib.Core.Auth;
+using ModpackLauncher.Models;
+using ModpackLauncher.Services;
+
+namespace ModpackLauncher;
+
+public partial class MainWindow : Window
+{
+    private enum LauncherState
+    {
+        Checking,        // initial / fetching manifest
+        ConfigError,     // manifest URL not set or unreachable + nothing local
+        NeedsDownload,   // no local pack, manifest reachable
+        NeedsUpdate,     // local pack version != manifest version
+        ReadyNotSignedIn,// up-to-date but not signed in
+        Ready            // up-to-date and signed in
+    }
+
+    private readonly LauncherConfig _config;
+    private readonly AuthService _auth;
+    private readonly ManifestSyncService _sync;
+    private LauncherSettings _settings;
+    private LaunchService? _launch;
+    private MSession? _session;
+    private Manifest? _remoteManifest;
+    private LauncherState _state = LauncherState.Checking;
+    private bool _busy;
+    private bool _suppressAutoSave;
+    private bool _infoPanelOpen;
+    // Cached "what the play button should show when not busy". Updated by ApplyState,
+    // restored by SetBusy(false). Avoids race between login flow's SetBusy and the
+    // RefreshStateAsync triggered by ApplySession.
+    private string _playButtonLabel = "Play";
+    private bool _playButtonEnabled;
+
+    public MainWindow()
+    {
+        InitializeComponent();
+
+        FileLog.Init();
+        _config = LauncherConfig.Load();
+        _auth = new AuthService(_config.MsalClientId);
+        _sync = new ManifestSyncService();
+        _sync.SetBasicAuth(_config.HttpUsername, _config.HttpPassword);
+
+        var version = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
+        var versionText = version is null ? "" : $" v{version.Major}.{version.Minor}.{version.Build}";
+        Title = $"{_config.PackName} Launcher{versionText}";
+        PackNameText.Text = _config.PackName;
+        TitleText.Text = $"{_config.PackName} Launcher{versionText}";
+
+        _settings = LauncherSettings.Load();
+
+        // Initialise RAM control without triggering auto-save
+        _suppressAutoSave = true;
+        RamBox.Value = _settings.MemoryMB ?? _config.MemoryMB;
+        _suppressAutoSave = false;
+        RamBox.ValueChanged += OnRamValueChanged;
+
+        UpdateInstallDirDisplay();
+        UpdateRamWarning((int)(RamBox.Value ?? _config.MemoryMB));
+
+        var localVersion = _sync.GetLocalPackVersion(GetInstallDir());
+        PackVersionText.Text = localVersion?.Version is { } v
+            ? $"Installed: v{v}"
+            : "No pack synced yet";
+
+        // Maximize is disabled on this launcher -- the slide-out animation gets unhappy
+        // when the window can't actually resize. If something (Win+Up, Aero Snap, etc.)
+        // pushes us to Maximized anyway, snap back to Normal.
+        PropertyChanged += (_, e) =>
+        {
+            if (e.Property == WindowStateProperty && WindowState == WindowState.Maximized)
+            {
+                WindowState = WindowState.Normal;
+            }
+        };
+
+        Opened += async (_, _) =>
+        {
+            CheckSystemRequirements();
+            await TrySilentSignInAsync();
+            await RefreshStateAsync(refetchManifest: true);
+        };
+
+        // Auto-refresh manifest when window regains focus (e.g. user alt-tabs back)
+        Activated += async (_, _) =>
+        {
+            if (_busy) return;
+            await RefreshStateAsync(refetchManifest: true);
+        };
+
+    }
+
+    private async void OnRefreshClick(object? sender, RoutedEventArgs e)
+    {
+        if (_busy) return;
+        _remoteManifest = null; // force a fresh fetch
+        await RefreshStateAsync(refetchManifest: true);
+    }
+
+    /// <summary>
+    /// Compare our running assembly version to the manifest's launcherVersion field.
+    /// If the manifest reports something newer, surface a non-blocking banner that
+    /// links to the public download URL. Doesn't auto-update -- friends decide when.
+    /// </summary>
+    private void CheckLauncherVersion(Manifest manifest)
+    {
+        UpdateBanner.IsVisible = false;
+        if (string.IsNullOrWhiteSpace(manifest.LauncherVersion)) return;
+
+        var current = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
+        if (current is null) return;
+        if (!Version.TryParse(manifest.LauncherVersion, out var advertised)) return;
+        if (current >= advertised) return;
+
+        UpdateBannerText.Text = $"A newer launcher (v{advertised}) is available -- you're on v{current.Major}.{current.Minor}.{current.Build}.";
+        UpdateBannerDownloadButton.Tag = manifest.LauncherUrl ?? "https://sijbers.uk/pack/BrassAndSigil-Launcher.exe";
+        UpdateBanner.IsVisible = true;
+        AppendLog($"[update] Newer launcher available: v{advertised} (running v{current})");
+    }
+
+    private void OnUpdateBannerDownloadClick(object? sender, RoutedEventArgs e)
+    {
+        var url = UpdateBannerDownloadButton.Tag as string
+                  ?? "https://sijbers.uk/pack/BrassAndSigil-Launcher.exe";
+        try
+        {
+            Process.Start(new ProcessStartInfo { FileName = url, UseShellExecute = true });
+        }
+        catch (Exception ex)
+        {
+            AppendLog($"[update] Couldn't open browser: {ex.Message}");
+        }
+    }
+
+    private const double InfoPanelExtraWidth = 334; // 320 panel + 14 gap
+
+    private void OnInfoClick(object? sender, RoutedEventArgs e)
+    {
+        _infoPanelOpen = !_infoPanelOpen;
+        ApplyInfoPanelState();
+    }
+
+    private void ApplyInfoPanelState()
+    {
+        var currentContainerWidth = InfoPanelContainer.Width;
+        var targetContainerWidth  = _infoPanelOpen ? InfoPanelExtraWidth : 0;
+        var deltaWidth            = targetContainerWidth - currentContainerWidth;
+
+        AnimateSlideOut(currentContainerWidth, targetContainerWidth, Width, Width + deltaWidth);
+    }
+
+    private DispatcherTimer? _widthAnimTimer;
+
+    private void AnimateSlideOut(double containerStart, double containerEnd,
+                                  double windowStart,    double windowEnd,
+                                  Action? onComplete = null)
+    {
+        _widthAnimTimer?.Stop();
+
+        var startTime = DateTime.UtcNow;
+        const double durationMs = 220;
+
+        _widthAnimTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(15) };
+        _widthAnimTimer.Tick += (_, _) =>
+        {
+            var elapsed = (DateTime.UtcNow - startTime).TotalMilliseconds;
+            var t = Math.Min(1.0, elapsed / durationMs);
+            var eased = 1 - Math.Pow(1 - t, 3); // ease-out cubic
+            // Animate both in lockstep so the Star column (RootBorder) keeps its width.
+            InfoPanelContainer.Width = containerStart + (containerEnd - containerStart) * eased;
+            Width                    = windowStart    + (windowEnd    - windowStart)    * eased;
+            if (t >= 1.0)
+            {
+                InfoPanelContainer.Width = containerEnd;
+                Width                    = windowEnd;
+                _widthAnimTimer?.Stop();
+                _widthAnimTimer = null;
+                onComplete?.Invoke();
+            }
+        };
+        _widthAnimTimer.Start();
+    }
+
+    private void PopulateInfoPanel()
+    {
+        InfoPanelContent.Children.Clear();
+        if (_remoteManifest is null)
+        {
+            InfoPanelContent.Children.Add(new TextBlock
+            {
+                Text = "Pack info will appear once the manifest has been fetched.",
+                Foreground = new SolidColorBrush(Color.Parse("#9F8E72")),
+                TextWrapping = TextWrapping.Wrap,
+                FontSize = 12
+            });
+            return;
+        }
+
+        AddInfoSection("Pack",
+            ("Name",    _remoteManifest.Name ?? "(unnamed)"),
+            ("Version", _remoteManifest.Version ?? "?"));
+
+        AddInfoSection("Minecraft",
+            ("Version", _remoteManifest.Minecraft.Version),
+            ("Loader",  _remoteManifest.Loader is null
+                ? "vanilla"
+                : $"{_remoteManifest.Loader.Type} {_remoteManifest.Loader.Version}"));
+
+        var modFiles = _remoteManifest.Files
+            .Where(f => f.Path.StartsWith("mods/", StringComparison.OrdinalIgnoreCase))
+            .ToList();
+        AddModListSection($"Mods ({modFiles.Count})", modFiles);
+
+        var others = _remoteManifest.Files
+            .Where(f => !f.Path.StartsWith("mods/", StringComparison.OrdinalIgnoreCase))
+            .ToList();
+        if (others.Count > 0)
+        {
+            AddOtherFilesSection($"Other files ({others.Count})", others);
+        }
+    }
+
+    private void AddInfoSection(string title, params (string Label, string Value)[] rows)
+    {
+        var stack = new StackPanel { Spacing = 4 };
+        stack.Children.Add(new TextBlock
+        {
+            Text = title.ToUpper(),
+            FontSize = 10,
+            FontWeight = FontWeight.Bold,
+            Foreground = new SolidColorBrush(Color.Parse("#E8B95C")),
+            Margin = new Thickness(0, 0, 0, 4)
+        });
+        foreach (var (label, value) in rows)
+        {
+            var row = new Grid { ColumnDefinitions = new ColumnDefinitions("Auto,*") };
+            row.Children.Add(new TextBlock
+            {
+                Text = label, Margin = new Thickness(0, 0, 8, 0),
+                Foreground = new SolidColorBrush(Color.Parse("#7A8497")),
+                FontSize = 12,
+                MinWidth = 60
+            });
+            var valueBlock = new TextBlock
+            {
+                Text = value,
+                Foreground = new SolidColorBrush(Color.Parse("#E8DFC8")),
+                FontSize = 12,
+                TextWrapping = TextWrapping.Wrap
+            };
+            Grid.SetColumn(valueBlock, 1);
+            row.Children.Add(valueBlock);
+            stack.Children.Add(row);
+        }
+        InfoPanelContent.Children.Add(stack);
+    }
+
+    private void AddModListSection(string title, System.Collections.Generic.List<ManifestFile> mods)
+    {
+        var stack = new StackPanel { Spacing = 6 };
+        stack.Children.Add(new TextBlock
+        {
+            Text = title.ToUpper(),
+            FontSize = 10,
+            FontWeight = FontWeight.Bold,
+            Foreground = new SolidColorBrush(Color.Parse("#E8B95C")),
+            Margin = new Thickness(0, 0, 0, 4)
+        });
+        foreach (var mod in mods)
+        {
+            var (name, version) = ParseModFilename(System.IO.Path.GetFileName(mod.Path));
+            var row = new StackPanel { Spacing = 1 };
+            row.Children.Add(new TextBlock
+            {
+                Text = name,
+                Foreground = new SolidColorBrush(Color.Parse("#E8DFC8")),
+                FontSize = 12,
+                FontWeight = FontWeight.Medium
+            });
+            row.Children.Add(new TextBlock
+            {
+                Text = version,
+                Foreground = new SolidColorBrush(Color.Parse("#7A8497")),
+                FontSize = 11
+            });
+            stack.Children.Add(row);
+        }
+        InfoPanelContent.Children.Add(stack);
+    }
+
+    private void AddOtherFilesSection(string title, System.Collections.Generic.List<ManifestFile> files)
+    {
+        var stack = new StackPanel { Spacing = 4 };
+        stack.Children.Add(new TextBlock
+        {
+            Text = title.ToUpper(),
+            FontSize = 10,
+            FontWeight = FontWeight.Bold,
+            Foreground = new SolidColorBrush(Color.Parse("#E8B95C")),
+            Margin = new Thickness(0, 0, 0, 4)
+        });
+        foreach (var f in files)
+        {
+            stack.Children.Add(new TextBlock
+            {
+                Text = f.Path,
+                Foreground = new SolidColorBrush(Color.Parse("#B7C0D6")),
+                FontSize = 11,
+                TextWrapping = TextWrapping.Wrap
+            });
+        }
+        InfoPanelContent.Children.Add(stack);
+    }
+
+    private static (string Name, string Version) ParseModFilename(string filename)
+    {
+        var stem = System.IO.Path.GetFileNameWithoutExtension(filename);
+        // Split on both '-' and '_' -- Modrinth filenames mix both conventions
+        // (e.g. Terralith_1.21.x_v2.5.8.jar uses underscores).
+        var parts = stem.Split(new[] { '-', '_' });
+
+        // Recognise version segments that start with a digit OR with 'v' followed
+        // by a digit (e.g. "v2.5.8"). Find the smallest index that matches so the
+        // entire trailing version chain is captured.
+        int versionIdx = -1;
+        for (int i = parts.Length - 1; i >= 0; i--)
+        {
+            var p = parts[i];
+            if (p.Length == 0) continue;
+            var c0 = p[0];
+            var startsWithDigit  = char.IsDigit(c0);
+            var startsWithVDigit = (c0 == 'v' || c0 == 'V') && p.Length >= 2 && char.IsDigit(p[1]);
+            if (startsWithDigit || startsWithVDigit) versionIdx = i;
+        }
+        if (versionIdx <= 0) return (stem, "");
+
+        var skipWords = new System.Collections.Generic.HashSet<string>(StringComparer.OrdinalIgnoreCase)
+        { "neoforge", "forge", "fabric", "bundled" };
+        var acronyms = new System.Collections.Generic.HashSet<string>(StringComparer.OrdinalIgnoreCase)
+        { "ftb", "tfmg", "jei", "rei", "emi", "ae2", "ic2", "kubejs", "rpl", "c2me", "yungs" };
+
+        var nameParts = parts.Take(versionIdx)
+            .Where(s => !skipWords.Contains(s))
+            .Select(s => acronyms.Contains(s) ? s.ToUpper() : (s.Length > 0 ? char.ToUpper(s[0]) + s.Substring(1) : s));
+        var name = string.Join(" ", nameParts);
+        if (string.IsNullOrWhiteSpace(name)) name = stem;
+        var version = string.Join("-", parts.Skip(versionIdx));
+        return (name, version);
+    }
+
+    private void OnTitleBarPressed(object? sender, PointerPressedEventArgs e)
+    {
+        if (e.GetCurrentPoint(this).Properties.IsLeftButtonPressed)
+        {
+            BeginMoveDrag(e);
+        }
+    }
+
+    private void OnMinimizeClick(object? sender, RoutedEventArgs e)
+    {
+        WindowState = WindowState.Minimized;
+    }
+
+    private void OnCloseClick(object? sender, RoutedEventArgs e)
+    {
+        Close();
+    }
+
+    private void CheckSystemRequirements()
+    {
+        // WebView2 Runtime is required for the default sign-in flow. Preinstalled on
+        // most modern Windows but not guaranteed -- surface a helpful message at startup.
+        if (!_auth.HasCustomClientId && !WebView2Check.IsInstalled())
+        {
+            AppendLog("[system] Microsoft Edge WebView2 Runtime not detected.");
+            AppendLog($"[system] Sign-in won't work until it's installed: {WebView2Check.DownloadUrl}");
+            UpdateStatus("WebView2 Runtime missing",
+                $"Sign-in needs Microsoft Edge WebView2 Runtime -- install from {WebView2Check.DownloadUrl}");
+        }
+    }
+
+    private async Task TrySilentSignInAsync()
+    {
+        var session = await _auth.TryAuthenticateSilentlyAsync();
+        if (session != null)
+        {
+            _session = session;
+            ApplySession(session);
+        }
+    }
+
+    private void ApplySession(MSession session)
+    {
+        _session = session;
+        UserText.Text = $"Signed in as {session.Username}";
+        LoginButton.IsVisible = false;
+        LogoutButton.IsVisible = true;
+        _ = RefreshStateAsync();
+        _ = RefreshWhitelistStatusAsync();
+    }
+
+    private void ClearSession()
+    {
+        _session = null;
+        UserText.Text = "Not signed in";
+        LoginButton.IsVisible = true;
+        LogoutButton.IsVisible = false;
+        WhitelistStatusText.IsVisible = false;
+        RequestAccessButton.IsVisible = false;
+        _ = RefreshStateAsync();
+    }
+
+    private async Task RefreshWhitelistStatusAsync()
+    {
+        if (_session is null || _remoteManifest is null) return;
+        var panelUrl = _remoteManifest.PanelUrl;
+        if (string.IsNullOrWhiteSpace(panelUrl))
+        {
+            // No panel configured in the manifest -- feature disabled.
+            WhitelistStatusText.IsVisible = false;
+            RequestAccessButton.IsVisible = false;
+            return;
+        }
+        var status = await new WhitelistRequestService().GetStatusAsync(panelUrl, _session.Username ?? "");
+        ApplyWhitelistStatus(status);
+    }
+
+    private void ApplyWhitelistStatus(string status)
+    {
+        // Status values: "pending", "approved", "denied", "unknown" (no record), "" (network error).
+        switch (status)
+        {
+            case "pending":
+                WhitelistStatusText.Text = "Whitelist request pending";
+                WhitelistStatusText.IsVisible = true;
+                RequestAccessButton.IsVisible = false;
+                break;
+            case "approved":
+                // Once approved, the server removes the record; this branch is rare
+                // (status returns "unknown" almost immediately after approve fires).
+                WhitelistStatusText.Text = "Whitelisted ✓";
+                WhitelistStatusText.IsVisible = true;
+                RequestAccessButton.IsVisible = false;
+                break;
+            case "denied":
+                WhitelistStatusText.Text = "Request denied";
+                WhitelistStatusText.IsVisible = true;
+                RequestAccessButton.IsVisible = true; // allow retry
+                RequestAccessButton.Content = "Request again";
+                break;
+            case "":
+                // Network error -- hide both, don't claim anything.
+                WhitelistStatusText.IsVisible = false;
+                RequestAccessButton.IsVisible = false;
+                break;
+            default: // "unknown" -- never requested
+                WhitelistStatusText.IsVisible = false;
+                RequestAccessButton.IsVisible = true;
+                RequestAccessButton.Content = "Request access";
+                break;
+        }
+    }
+
+    private async void OnRequestAccessClick(object? sender, RoutedEventArgs e)
+    {
+        if (_session is null || _remoteManifest?.PanelUrl is not { } panelUrl) return;
+        RequestAccessButton.IsEnabled = false;
+        try
+        {
+            var resp = await new WhitelistRequestService().SubmitAsync(panelUrl, _session.Username ?? "", null);
+            if (resp.Ok)
+            {
+                AppendLog($"[whitelist] Request sent for {_session.Username}.");
+                ApplyWhitelistStatus("pending");
+            }
+            else
+            {
+                AppendLog($"[whitelist] Request failed: {resp.Error ?? "unknown"}");
+                UpdateStatus("Request failed", resp.Error ?? "Couldn't reach server.");
+            }
+        }
+        finally { RequestAccessButton.IsEnabled = true; }
+    }
+
+    private async Task RefreshStateAsync(bool refetchManifest = false)
+    {
+        if (_busy) return;
+
+        if (string.IsNullOrWhiteSpace(_config.ManifestUrl) ||
+            _config.ManifestUrl.Contains("example.com"))
+        {
+            ApplyState(LauncherState.ConfigError, "Setup needed",
+                "Set 'manifestUrl' in launcher-config.json and rebuild.");
+            return;
+        }
+
+        if (refetchManifest || _remoteManifest == null)
+        {
+            ApplyState(LauncherState.Checking, "Checking...", "Looking for updates");
+            try
+            {
+                _remoteManifest = await _sync.FetchManifestOnlyAsync(_config.ManifestUrl);
+                PopulateInfoPanel();
+                CheckLauncherVersion(_remoteManifest);
+                _ = RefreshWhitelistStatusAsync();
+            }
+            catch (Exception ex)
+            {
+                AppendLog($"[manifest fetch] {ex.GetType().Name}: {ex.Message}");
+                // Offline fallback -- allow play if we have a local pack
+                var fallback = _sync.GetLocalPackVersion(GetInstallDir());
+                if (fallback?.Version != null)
+                {
+                    if (_session != null)
+                    {
+                        ApplyState(LauncherState.Ready, "Play",
+                            $"Offline: pack server unreachable, using local v{fallback.Version}");
+                    }
+                    else
+                    {
+                        ApplyState(LauncherState.ReadyNotSignedIn, "Play",
+                            "Offline mode -- sign in to play");
+                    }
+                }
+                else
+                {
+                    ApplyState(LauncherState.ConfigError, "Connection error",
+                        $"Couldn't reach pack server: {ex.Message}");
+                }
+                return;
+            }
+        }
+
+        var local = _sync.GetLocalPackVersion(GetInstallDir());
+        var remote = _remoteManifest!;
+
+        if (local == null)
+        {
+            ApplyState(LauncherState.NeedsDownload, "Download",
+                $"{remote.Name ?? "Pack"} v{remote.Version ?? "?"} ready to download");
+            return;
+        }
+
+        if (!string.Equals(local.Version, remote.Version, StringComparison.Ordinal))
+        {
+            ApplyState(LauncherState.NeedsUpdate, "Update",
+                $"Update available: v{local.Version} → v{remote.Version}");
+            return;
+        }
+
+        // Version matches -- but also verify the actual files are on disk. Catches AV
+        // quarantines, manual deletions, and interrupted downloads.
+        var missing = _sync.FindMissingFiles(remote, GetInstallDir());
+        if (missing.Count > 0)
+        {
+            ApplyState(LauncherState.NeedsUpdate, "Repair",
+                $"Pack files missing ({missing.Count}). Click to redownload.");
+            return;
+        }
+
+        if (_session == null)
+        {
+            ApplyState(LauncherState.ReadyNotSignedIn, "Play",
+                $"Up to date (v{local.Version}). Sign in to play.");
+        }
+        else
+        {
+            ApplyState(LauncherState.Ready, "Play",
+                $"Up to date (v{local.Version}). Ready to launch.");
+        }
+    }
+
+    private void ApplyState(LauncherState state, string buttonLabel, string subtext)
+    {
+        _state = state;
+        _playButtonLabel = buttonLabel;
+        _playButtonEnabled = state is LauncherState.NeedsDownload
+                                   or LauncherState.NeedsUpdate
+                                   or LauncherState.Ready;
+        if (!_busy)
+        {
+            PlayButton.Content = _playButtonLabel;
+            PlayButton.IsEnabled = _playButtonEnabled;
+        }
+        StatusText.Text = state switch
+        {
+            LauncherState.Ready or LauncherState.ReadyNotSignedIn => "Ready",
+            LauncherState.NeedsDownload => "Download required",
+            LauncherState.NeedsUpdate   => "Update available",
+            LauncherState.Checking      => "Checking...",
+            LauncherState.ConfigError   => "Setup needed",
+            _                           => "..."
+        };
+        StatusSubtext.Text = subtext;
+    }
+
+    private async void OnLoginClick(object? sender, RoutedEventArgs e)
+    {
+        if (_busy) return;
+        try
+        {
+            SetBusy(true);
+            UpdateStatus("Signing in...", "A browser window should appear.");
+            var session = await _auth.SignInInteractivelyAsync();
+            ApplySession(session);
+            UpdateStatus("Signed in", $"Welcome, {session.Username}.");
+        }
+        catch (Exception ex)
+        {
+            LogException("auth error", ex);
+            UpdateStatus("Sign-in failed", ex.Message);
+        }
+        finally
+        {
+            SetBusy(false);
+            // ApplySession's fire-and-forget RefreshStateAsync was a no-op because
+            // _busy was still true. Re-run state now that we're idle so the Play
+            // button enables based on the new session + current pack state.
+            await RefreshStateAsync();
+        }
+    }
+
+    private void LogException(string label, Exception ex)
+    {
+        AppendLog($"[{label}] {ex.GetType().Name}: {ex.Message}");
+        var inner = ex.InnerException;
+        var depth = 0;
+        while (inner != null && depth < 5)
+        {
+            AppendLog($"  ↳ {inner.GetType().Name}: {inner.Message}");
+            inner = inner.InnerException;
+            depth++;
+        }
+        // Reflectively surface any Code / XErr / Redirect / StatusCode properties (XboxAuthException, etc.)
+        foreach (var prop in ex.GetType().GetProperties())
+        {
+            if (prop.Name is "Code" or "XErr" or "ErrorCode" or "StatusCode" or "Redirect" or "Identity" or "Message" or "Source" or "InnerException" or "TargetSite" or "StackTrace" or "Data" or "HelpLink" or "HResult")
+            {
+                if (prop.Name is "Message" or "Source" or "InnerException" or "TargetSite" or "StackTrace" or "Data" or "HelpLink" or "HResult") continue;
+                try
+                {
+                    var val = prop.GetValue(ex);
+                    if (val != null) AppendLog($"  • {prop.Name}: {val}");
+                }
+                catch { }
+            }
+        }
+    }
+
+    private async void OnLogoutClick(object? sender, RoutedEventArgs e)
+    {
+        await _auth.SignOutAsync();
+        ClearSession();
+        UpdateStatus("Signed out", "Click Sign in to authenticate again.");
+    }
+
+    private async void OnPlayClick(object? sender, RoutedEventArgs e)
+    {
+        if (_busy) return;
+
+        switch (_state)
+        {
+            case LauncherState.NeedsDownload:
+            case LauncherState.NeedsUpdate:
+                await DoSyncAndInstallAsync();
+                break;
+            case LauncherState.Ready:
+                await DoLaunchAsync();
+                break;
+            // Other states leave the button disabled -- shouldn't reach here.
+        }
+    }
+
+    private async Task DoSyncAndInstallAsync()
+    {
+        try
+        {
+            SetBusy(true);
+            var installDir = GetInstallDir();
+            Directory.CreateDirectory(installDir);
+            var progress = new Progress<ProgressReport>(OnProgress);
+
+            UpdateStatus("Syncing pack...", "Fetching manifest and downloading mods.");
+            var syncResult = await _sync.SyncAsync(_config.ManifestUrl, installDir, progress);
+            _remoteManifest = syncResult.Manifest;
+            AppendLog($"Sync: {syncResult.Downloaded} downloaded, {syncResult.Removed} removed.");
+
+            PackVersionText.Text = syncResult.Manifest.Version is { } v
+                ? $"Installed: v{v}"
+                : "Installed";
+
+            // Pre-populate the multiplayer server list so friends don't have to
+            // hand-type the address. Idempotent -- match-by-IP, won't duplicate.
+            if (syncResult.Manifest.DefaultServer is { } ds && !string.IsNullOrEmpty(ds.Ip))
+            {
+                try
+                {
+                    new ServerListService().EnsureServer(installDir, ds.Name, ds.Ip);
+                    AppendLog($"Multiplayer list seeded: {ds.Name} ({ds.Ip}).");
+                }
+                catch (Exception ex)
+                {
+                    AppendLog($"[server-list] Couldn't update servers.dat: {ex.Message}");
+                }
+            }
+
+            // Pre-enable a default shader pack on fresh installs (Iris reads
+            // config/iris.properties at startup). Does nothing if the user has
+            // already chosen a different shader.
+            if (!string.IsNullOrEmpty(syncResult.Manifest.DefaultShader))
+            {
+                try
+                {
+                    new IrisConfigService().SetDefaultShader(installDir, syncResult.Manifest.DefaultShader);
+                    AppendLog($"Default shader: {syncResult.Manifest.DefaultShader} (only set if no shader was previously chosen).");
+                }
+                catch (Exception ex)
+                {
+                    AppendLog($"[iris] Couldn't set default shader: {ex.Message}");
+                }
+            }
+
+            _launch ??= new LaunchService(installDir);
+            UpdateStatus("Installing Minecraft...",
+                "Downloading client, libraries, assets, and mod loader. First run may take a few minutes.");
+            var versionId = await _launch.InstallVersionAsync(
+                syncResult.Manifest, progress, CancellationToken.None);
+            AppendLog($"Version ready: {versionId}");
+            ResetProgress();
+        }
+        catch (Exception ex)
+        {
+            AppendLog($"[error] {ex.GetType().Name}: {ex.Message}");
+            UpdateStatus("Install failed", ex.Message);
+        }
+        finally
+        {
+            SetBusy(false);
+            await RefreshStateAsync();
+        }
+    }
+
+    private async Task DoLaunchAsync()
+    {
+        if (_session == null || _remoteManifest == null) return;
+
+        try
+        {
+            SetBusy(true);
+            var progress = new Progress<ProgressReport>(OnProgress);
+            var installDir = GetInstallDir();
+            _launch ??= new LaunchService(installDir);
+
+            // Pre-launch sanity: any manifest files missing? If so, re-sync.
+            var missing = _sync.FindMissingFiles(_remoteManifest, installDir);
+            if (missing.Count > 0)
+            {
+                UpdateStatus("Repairing pack...",
+                    $"{missing.Count} file(s) missing -- redownloading before launch.");
+                AppendLog($"Pre-launch check: {missing.Count} files missing, re-syncing.");
+                var syncResult = await _sync.SyncAsync(_config.ManifestUrl, installDir, progress);
+                _remoteManifest = syncResult.Manifest;
+                AppendLog($"Re-sync: {syncResult.Downloaded} downloaded, {syncResult.Removed} removed.");
+            }
+
+            UpdateStatus("Verifying installation...",
+                "Checking Minecraft, mod loader, and libraries.");
+            // InstallVersionAsync is idempotent + always runs the library verifier afterwards,
+            // so this catches any post-install gaps (e.g. CmlLib's bootstraplauncher quirk).
+            var versionId = await _launch.InstallVersionAsync(
+                _remoteManifest, progress, CancellationToken.None);
+
+            var ram = (int)(RamBox.Value ?? _config.MemoryMB);
+            var minRam = ram;
+            var maxRam = ram;
+
+            UpdateStatus("Launching Minecraft...", "");
+            ResetProgress();
+
+            _ = Task.Run(async () =>
+            {
+                try
+                {
+                    await _launch.LaunchAsync(versionId, _session!, minRam, maxRam, progress, CancellationToken.None);
+                }
+                catch (Exception ex)
+                {
+                    await Dispatcher.UIThread.InvokeAsync(() =>
+                    {
+                        AppendLog($"[launch error] {ex.GetType().Name}: {ex.Message}");
+                        UpdateStatus("Launch failed", ex.Message);
+                    });
+                }
+                finally
+                {
+                    await Dispatcher.UIThread.InvokeAsync(async () =>
+                    {
+                        SetBusy(false);
+                        await RefreshStateAsync();
+                    });
+                }
+            });
+        }
+        catch (Exception ex)
+        {
+            AppendLog($"[error] {ex.GetType().Name}: {ex.Message}");
+            UpdateStatus("Launch failed", ex.Message);
+            SetBusy(false);
+            await RefreshStateAsync();
+        }
+    }
+
+    private string GetInstallDir() => _config.GetInstallDir(_settings.InstallDirOverride);
+
+    private void UpdateInstallDirDisplay()
+    {
+        InstallDirText.Text = GetInstallDir();
+    }
+
+    private void UpdateRamWarning(int ramMb)
+    {
+        var totalMb = SystemInfo.TotalPhysicalMemoryMB;
+        var safeMax = SystemInfo.SafeMaxAllocationMB;
+
+        if (totalMb < 12 * 1024)
+        {
+            RamWarningText.Text = $"Only {totalMb / 1024} GB system RAM detected -- pack may not run smoothly (12+ GB recommended)";
+            RamWarningText.Foreground = new SolidColorBrush(Color.Parse("#E8B95C"));
+        }
+        else if (ramMb > safeMax)
+        {
+            RamWarningText.Text = $"Above safe limit for {totalMb / 1024} GB system (max {safeMax} MB recommended)";
+            RamWarningText.Foreground = new SolidColorBrush(Color.Parse("#DC6E28"));
+        }
+        else if (ramMb < 6144)
+        {
+            RamWarningText.Text = "Below recommended (6 GB+ for Distant Horizons)";
+            RamWarningText.Foreground = new SolidColorBrush(Color.Parse("#9F8E72"));
+        }
+        else
+        {
+            RamWarningText.Text = $"OK ({totalMb / 1024} GB system)";
+            RamWarningText.Foreground = new SolidColorBrush(Color.Parse("#7A8497"));
+        }
+    }
+
+    private void OnRamValueChanged(object? sender, NumericUpDownValueChangedEventArgs e)
+    {
+        if (_suppressAutoSave) return;
+        var ram = (int)(RamBox.Value ?? _config.MemoryMB);
+        _settings.MemoryMB = ram;
+        _settings.Save();
+        UpdateRamWarning(ram);
+    }
+
+    private async void OnChangeInstallDirClick(object? sender, RoutedEventArgs e)
+    {
+        var folders = await StorageProvider.OpenFolderPickerAsync(new FolderPickerOpenOptions
+        {
+            Title = "Choose install location",
+            AllowMultiple = false
+        });
+        if (folders.Count == 0) return;
+
+        var picked = folders[0].TryGetLocalPath();
+        if (string.IsNullOrEmpty(picked)) return;
+
+        _settings.InstallDirOverride = picked;
+        _settings.Save();
+        UpdateInstallDirDisplay();
+        AppendLog($"Install location changed to: {picked}");
+        AppendLog("Pack will need to be re-downloaded at the new location on next Play.");
+
+        _launch = null; // force re-create with new path next time
+        _remoteManifest = null;
+        await RefreshStateAsync(refetchManifest: true);
+    }
+
+    private void OnOpenFolderClick(object? sender, RoutedEventArgs e)
+    {
+        var dir = GetInstallDir();
+        Directory.CreateDirectory(dir);
+        try
+        {
+            Process.Start(new ProcessStartInfo
+            {
+                FileName = dir,
+                UseShellExecute = true
+            });
+        }
+        catch (Exception ex)
+        {
+            AppendLog($"[open folder] {ex.Message}");
+        }
+    }
+
+    private void OnProgress(ProgressReport report)
+    {
+        if (Dispatcher.UIThread.CheckAccess())
+        {
+            ApplyProgress(report);
+        }
+        else
+        {
+            Dispatcher.UIThread.Post(() => ApplyProgress(report));
+        }
+    }
+
+    private void ApplyProgress(ProgressReport report)
+    {
+        switch (report.Kind)
+        {
+            case ProgressKind.Status:
+                StatusSubtext.Text = report.Message;
+                break;
+            case ProgressKind.Progress:
+                if (report.Percent >= 0) ProgressBar.Value = Math.Clamp(report.Percent, 0, 100);
+                StatusSubtext.Text = report.Message;
+                break;
+            case ProgressKind.Log:
+                AppendLog(report.Message);
+                break;
+            case ProgressKind.Error:
+                AppendLog($"[error] {report.Message}");
+                break;
+        }
+    }
+
+    private void UpdateStatus(string title, string subtitle)
+    {
+        StatusText.Text = title;
+        StatusSubtext.Text = subtitle;
+    }
+
+    private void ResetProgress()
+    {
+        ProgressBar.Value = 0;
+    }
+
+    private void AppendLog(string message)
+    {
+        if (string.IsNullOrEmpty(message)) return;
+        LogText.Text += (LogText.Text?.Length > 0 ? "\n" : "") + message;
+        LogScroll.ScrollToEnd();
+        FileLog.Write(message);
+    }
+
+    private void SetBusy(bool busy)
+    {
+        _busy = busy;
+        if (busy)
+        {
+            PlayButton.IsEnabled = false;
+            PlayButton.Content = "Working...";
+        }
+        else
+        {
+            // Restore from the cached state-derived label (avoids races with concurrent state refreshes).
+            PlayButton.Content = _playButtonLabel;
+            PlayButton.IsEnabled = _playButtonEnabled;
+        }
+        LoginButton.IsEnabled = !busy;
+        LogoutButton.IsEnabled = !busy;
+    }
+}

launcher/Models/LauncherConfig.cs

@@ -0,0 +1,106 @@
+using System;
+using System.IO;
+using System.Reflection;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace ModpackLauncher.Models;
+
+public sealed class LauncherConfig
+{
+    [JsonPropertyName("packName")]
+    public string PackName { get; set; } = "Modpack";
+
+    [JsonPropertyName("manifestUrl")]
+    public string ManifestUrl { get; set; } = "";
+
+    /// <summary>
+    /// Subfolder name appended under the install location (sidecar exe folder
+    /// by default, or the folder the user picked via "Change..."). Acts as
+    /// a safety net so picking a generic location like "D:\" doesn't dump
+    /// thousands of files at the drive root, and signals at a glance that
+    /// this is the launcher's data, not the launcher itself.
+    /// </summary>
+    [JsonPropertyName("installDirName")]
+    public string InstallDirName { get; set; } = "BrassAndSigilData";
+
+    [JsonPropertyName("memoryMB")]
+    public int MemoryMB { get; set; } = 8192;
+
+    [JsonPropertyName("msalClientId")]
+    public string MsalClientId { get; set; } = "";
+
+    /// <summary>Optional HTTP Basic auth username for the manifest URL and mod file URLs.</summary>
+    [JsonPropertyName("httpUsername")]
+    public string? HttpUsername { get; set; }
+
+    /// <summary>Optional HTTP Basic auth password (paired with HttpUsername).</summary>
+    [JsonPropertyName("httpPassword")]
+    public string? HttpPassword { get; set; }
+
+    public static LauncherConfig Load()
+    {
+        // 1. External override beside the exe (dev convenience / per-deploy override)
+        var sidecar = Path.Combine(AppContext.BaseDirectory, "launcher-config.json");
+        if (File.Exists(sidecar))
+        {
+            return ParseSafe(File.ReadAllText(sidecar));
+        }
+
+        // 2. Embedded launcher-config.json (set at build time from local copy)
+        var asm = typeof(LauncherConfig).Assembly;
+        using (var stream = asm.GetManifestResourceStream("launcher-config.json"))
+        {
+            if (stream != null)
+            {
+                using var reader = new StreamReader(stream);
+                return ParseSafe(reader.ReadToEnd());
+            }
+        }
+
+        // 3. Fall back to embedded template (so fresh clones still run, with placeholders)
+        using (var stream = asm.GetManifestResourceStream("launcher-config.template.json"))
+        {
+            if (stream != null)
+            {
+                using var reader = new StreamReader(stream);
+                return ParseSafe(reader.ReadToEnd());
+            }
+        }
+
+        return new LauncherConfig();
+    }
+
+    private static LauncherConfig ParseSafe(string json)
+    {
+        var opts = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
+        return JsonSerializer.Deserialize<LauncherConfig>(json, opts) ?? new LauncherConfig();
+    }
+
+    /// <summary>
+    /// Resolve the absolute install directory. The launcher behaves as a
+    /// portable app: by default it installs alongside the exe in
+    /// <c>&lt;exe-folder&gt;/&lt;InstallDirName&gt;/</c>. The user can override
+    /// via the "Change..." picker, which stores the chosen *parent* folder
+    /// in <c>InstallDirOverride</c>; we then append <see cref="InstallDirName"/>
+    /// to it (same safety reasoning as the default).
+    ///
+    /// Smart-skip: if the parent path already ends in InstallDirName, we
+    /// don't double up. Lets users re-pick their existing install folder
+    /// (e.g. "D:\Games\BrassAndSigilData") without ending up at
+    /// "D:\Games\BrassAndSigilData\BrassAndSigilData".
+    /// </summary>
+    public string GetInstallDir(string? overrideDir = null)
+    {
+        var parent = !string.IsNullOrWhiteSpace(overrideDir)
+            ? overrideDir!
+            : AppContext.BaseDirectory;
+
+        var trimmed = parent.TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
+        if (string.Equals(Path.GetFileName(trimmed), InstallDirName, StringComparison.OrdinalIgnoreCase))
+        {
+            return trimmed;
+        }
+        return Path.Combine(parent, InstallDirName);
+    }
+}

launcher/Models/LauncherSettings.cs

@@ -0,0 +1,54 @@
+using System;
+using System.IO;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace ModpackLauncher.Models;
+
+public sealed class LauncherSettings
+{
+    [JsonPropertyName("memoryMB")]
+    public int? MemoryMB { get; set; }
+
+    [JsonPropertyName("installDirOverride")]
+    public string? InstallDirOverride { get; set; }
+
+    /// <summary>
+    /// Settings live next to the launcher exe ("sidecar"), so each copy of
+    /// the launcher has its own independent state. Drop the launcher in a
+    /// new folder on a different machine, or alongside the existing one in
+    /// a separate directory, and they remember their own install paths,
+    /// memory choices, etc. Matches the portable-app convention.
+    /// </summary>
+    private static string FilePath
+        => Path.Combine(AppContext.BaseDirectory, "launcher-settings.json");
+
+    public static LauncherSettings Load()
+    {
+        try
+        {
+            if (!File.Exists(FilePath)) return new LauncherSettings();
+            return JsonSerializer.Deserialize<LauncherSettings>(File.ReadAllText(FilePath))
+                   ?? new LauncherSettings();
+        }
+        catch
+        {
+            return new LauncherSettings();
+        }
+    }
+
+    public void Save()
+    {
+        try
+        {
+            File.WriteAllText(
+                FilePath,
+                JsonSerializer.Serialize(this, new JsonSerializerOptions { WriteIndented = true })
+            );
+        }
+        catch
+        {
+            // best-effort
+        }
+    }
+}

launcher/Models/Manifest.cs

@@ -0,0 +1,110 @@
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace ModpackLauncher.Models;
+
+public sealed class Manifest
+{
+    [JsonPropertyName("name")]
+    public string? Name { get; set; }
+
+    [JsonPropertyName("version")]
+    public string? Version { get; set; }
+
+    [JsonPropertyName("minecraft")]
+    public MinecraftSpec Minecraft { get; set; } = new();
+
+    [JsonPropertyName("loader")]
+    public LoaderSpec? Loader { get; set; }
+
+    [JsonPropertyName("files")]
+    public List<ManifestFile> Files { get; set; } = new();
+
+    /// <summary>
+    /// Optional. The launcher version that the modpack publisher expects clients
+    /// to be running. If a client's assembly version is lower than this, the launcher
+    /// surfaces a "newer version available" banner pointing at <see cref="LauncherUrl"/>.
+    /// </summary>
+    [JsonPropertyName("launcherVersion")]
+    public string? LauncherVersion { get; set; }
+
+    /// <summary>Public download URL for the latest launcher (shown in the banner).</summary>
+    [JsonPropertyName("launcherUrl")]
+    public string? LauncherUrl { get; set; }
+
+    /// <summary>
+    /// Optional. If present, the launcher writes this entry into the player's
+    /// <c>servers.dat</c> on first install so the modpack's server appears in
+    /// the multiplayer list automatically -- no copy-paste needed.
+    /// </summary>
+    [JsonPropertyName("defaultServer")]
+    public DefaultServer? DefaultServer { get; set; }
+
+    /// <summary>
+    /// Optional. Filename (in shaderpacks/) of a shader pack to enable by default
+    /// for fresh installs. Existing installs with a different shader chosen are
+    /// left alone -- this is a default, not a forced override.
+    /// </summary>
+    [JsonPropertyName("defaultShader")]
+    public string? DefaultShader { get; set; }
+
+    /// <summary>
+    /// Optional. Public base URL of the brass-sigil-server admin panel (e.g.
+    /// https://bns-admin.sijbers.uk). The launcher uses this to send whitelist
+    /// requests on the player's behalf -- nothing else.
+    /// </summary>
+    [JsonPropertyName("panelUrl")]
+    public string? PanelUrl { get; set; }
+}
+
+public sealed class DefaultServer
+{
+    [JsonPropertyName("name")]
+    public string Name { get; set; } = "";
+
+    [JsonPropertyName("ip")]
+    public string Ip { get; set; } = "";
+}
+
+public sealed class MinecraftSpec
+{
+    [JsonPropertyName("version")]
+    public string Version { get; set; } = "";
+}
+
+public sealed class LoaderSpec
+{
+    /// <summary>"forge" | "fabric" | "neoforge" | "vanilla" (or null)</summary>
+    [JsonPropertyName("type")]
+    public string Type { get; set; } = "vanilla";
+
+    [JsonPropertyName("version")]
+    public string Version { get; set; } = "";
+}
+
+public sealed class ManifestFile
+{
+    [JsonPropertyName("path")]
+    public string Path { get; set; } = "";
+
+    [JsonPropertyName("url")]
+    public string Url { get; set; } = "";
+
+    [JsonPropertyName("sha1")]
+    public string? Sha1 { get; set; }
+
+    [JsonPropertyName("size")]
+    public long? Size { get; set; }
+}
+
+public sealed class PackVersionRecord
+{
+    [JsonPropertyName("name")]
+    public string? Name { get; set; }
+
+    [JsonPropertyName("version")]
+    public string? Version { get; set; }
+
+    [JsonPropertyName("syncedAt")]
+    public string? SyncedAt { get; set; }
+}

launcher/ModpackLauncher.csproj

@@ -0,0 +1,65 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <!-- net8.0-windows is required for the XboxAuthNet WebView2 OAuth flow:
+         the netstandard2.0 build of XboxAuthNet has no WebUI implementation. -->
+    <TargetFramework>net8.0-windows</TargetFramework>
+    <UseWindowsForms>true</UseWindowsForms>
+    <Nullable>enable</Nullable>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
+    <AvaloniaUseCompiledBindingsByDefault>true</AvaloniaUseCompiledBindingsByDefault>
+    <RootNamespace>ModpackLauncher</RootNamespace>
+    <AssemblyName>ModpackLauncher</AssemblyName>
+    <Version>0.4.5</Version>
+    <ApplicationIcon Condition="Exists('Assets\icon.ico')">Assets\icon.ico</ApplicationIcon>
+
+    <!-- Single-file self-contained publish defaults (Windows-only now due to WebView2) -->
+    <RuntimeIdentifier Condition="'$(RuntimeIdentifier)' == ''">win-x64</RuntimeIdentifier>
+    <RuntimeIdentifiers>win-x64</RuntimeIdentifiers>
+    <PublishSingleFile>true</PublishSingleFile>
+    <SelfContained>true</SelfContained>
+    <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
+    <EnableCompressionInSingleFile>true</EnableCompressionInSingleFile>
+    <DebugType>embedded</DebugType>
+    <CopyDebugSymbolFilesFromPackages>false</CopyDebugSymbolFilesFromPackages>
+    <CopyDocumentationFilesFromPackages>false</CopyDocumentationFilesFromPackages>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Avalonia" Version="12.0.2" />
+    <PackageReference Include="Avalonia.Desktop" Version="12.0.2" />
+    <PackageReference Include="Avalonia.Themes.Fluent" Version="12.0.2" />
+    <PackageReference Include="Avalonia.Fonts.Inter" Version="12.0.2" />
+    <PackageReference Include="AvaloniaUI.DiagnosticsSupport" Version="2.2.1">
+      <IncludeAssets Condition="'$(Configuration)' != 'Debug'">None</IncludeAssets>
+      <PrivateAssets Condition="'$(Configuration)' != 'Debug'">All</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="CmlLib.Core" Version="4.0.6" />
+    <PackageReference Include="CmlLib.Core.Auth.Microsoft" Version="3.3.1" />
+    <PackageReference Include="CmlLib.Core.Installer.Forge" Version="1.1.1" />
+    <PackageReference Include="CmlLib.Core.Installer.NeoForge" Version="4.0.0" />
+    <PackageReference Include="XboxAuthNet.Game.Msal" Version="0.1.3" />
+    <PackageReference Include="fNbt" Version="0.7.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <EmbeddedResource Include="launcher-config.json" Condition="Exists('launcher-config.json')">
+      <LogicalName>launcher-config.json</LogicalName>
+    </EmbeddedResource>
+    <EmbeddedResource Include="launcher-config.template.json">
+      <LogicalName>launcher-config.template.json</LogicalName>
+    </EmbeddedResource>
+  </ItemGroup>
+
+  <ItemGroup>
+    <AvaloniaResource Include="Assets\icon.png" />
+    <AvaloniaResource Include="Assets\noise.png" />
+  </ItemGroup>
+
+  <Target Name="StripNativePdbs" AfterTargets="Publish">
+    <ItemGroup>
+      <_StripPdb Include="$(PublishDir)*.pdb" Exclude="$(PublishDir)$(AssemblyName).pdb" />
+    </ItemGroup>
+    <Delete Files="@(_StripPdb)" />
+  </Target>
+</Project>

launcher/Program.cs

@@ -0,0 +1,24 @@
+using Avalonia;
+using System;
+
+namespace ModpackLauncher;
+
+class Program
+{
+    // Initialization code. Don't use any Avalonia, third-party APIs or any
+    // SynchronizationContext-reliant code before AppMain is called: things aren't initialized
+    // yet and stuff might break.
+    [STAThread]
+    public static void Main(string[] args) => BuildAvaloniaApp()
+        .StartWithClassicDesktopLifetime(args);
+
+    // Avalonia configuration, don't remove; also used by visual designer.
+    public static AppBuilder BuildAvaloniaApp()
+        => AppBuilder.Configure<App>()
+            .UsePlatformDetect()
+#if DEBUG
+            .WithDeveloperTools()
+#endif
+            .WithInterFont()
+            .LogToTrace();
+}

launcher/README.md

@@ -0,0 +1,112 @@
+# Brass & Sigil Launcher
+
+A custom Minecraft Java Edition launcher built for distributing the private
+"Brass & Sigil" modpack (Create + aeronautics + tech + magic + Distant
+Horizons) to a small friend group.
+
+> **NOT AN OFFICIAL MINECRAFT PRODUCT. NOT APPROVED BY OR ASSOCIATED WITH
+> MOJANG OR MICROSOFT.**
+
+## What it does
+
+1. Fetches a JSON manifest from a self-hosted server and syncs the modpack
+   files (mods, configs, resourcepacks) to the player's local install
+   directory. SHA-1 hashing ensures only changed files are downloaded.
+2. Authenticates each player with their own personal Microsoft account via
+   the standard MSAL OAuth + Xbox Live + Minecraft Services chain, using the
+   open-source `CmlLib.Core.Auth.Microsoft` library without modification.
+3. Installs the appropriate Minecraft Java Edition version and Forge mod
+   loader, then launches the game with the player's authenticated session.
+
+## Stack
+
+- **C# / .NET 8**
+- **Avalonia 12** -- desktop UI
+- **CmlLib.Core 4.x** -- Minecraft install + launch
+- **CmlLib.Core.Auth.Microsoft 3.x + XboxAuthNet.Game.Msal** -- Microsoft auth
+- **CmlLib.Core.Installer.Forge** -- Forge support
+
+## Build
+
+Requires the .NET 8 SDK.
+
+```powershell
+dotnet build
+```
+
+To produce the shippable single-file executable (~46 MB):
+
+```powershell
+dotnet publish -c Release -r win-x64 --self-contained true
+```
+
+Output: `bin/Release/net8.0/win-x64/publish/ModpackLauncher.exe` -- a single
+file with no other dependencies, ready to send to a friend.
+
+## Configuration
+
+The repo ships with a `launcher-config.template.json`. Copy it to
+`launcher-config.json` and fill in real values before building:
+
+```powershell
+Copy-Item launcher-config.template.json launcher-config.json
+```
+
+`launcher-config.json` is gitignored so local values (manifest URL, Azure
+client ID) never get committed.
+
+### Fields
+
+| Field | Purpose |
+| --- | --- |
+| `packName` | Display name shown in the launcher |
+| `manifestUrl` | URL of the hosted manifest JSON |
+| `installDirName` | Folder name under `%APPDATA%` for game files |
+| `memoryMinMB` / `memoryMaxMB` | JVM memory defaults |
+| `msalClientId` | Azure App Registration client ID for Microsoft auth |
+
+The config is **embedded into the exe** at build time, so the launcher ships
+as a single self-contained file. A sidecar `launcher-config.json` placed
+beside the exe will override the embedded copy at runtime (handy for testing).
+
+## Manifest format
+
+See `manifest.example.json` for the schema. Minimum:
+
+```json
+{
+  "name": "Brass & Sigil",
+  "version": "1.0.0",
+  "minecraft": { "version": "1.20.1" },
+  "loader": { "type": "forge", "version": "47.2.0" },
+  "files": [
+    { "path": "mods/example.jar", "url": "https://...", "sha1": "..." }
+  ]
+}
+```
+
+The launcher diffs the manifest against the local install dir using SHA-1
+hashes and downloads only what has changed. Files removed from the manifest
+are pruned from managed folders (`mods/`, `config/`, `resourcepacks/`,
+`shaderpacks/`, `kubejs/`, `defaultconfigs/`).
+
+## Privacy
+
+The launcher does not collect, store, or transmit any user data beyond what
+the standard Microsoft and Minecraft authentication APIs require. Auth tokens
+are cached locally via the MSAL token cache. No telemetry, no analytics, no
+third-party services beyond Microsoft and Mojang.
+
+Local data is written to:
+
+- `%APPDATA%\BrassAndSigil\` -- launcher settings + log file
+- `%APPDATA%\<installDirName>\` -- modpack and Minecraft installation
+
+## License
+
+MIT -- see [LICENSE](LICENSE).
+
+## Author
+
+Matt Sijbers -- [https://sijbers.uk/matt](https://sijbers.uk/matt) /
+[project page](https://sijbers.uk/brass-and-sigil)

launcher/Services/AuthService.cs

@@ -0,0 +1,95 @@
+using System;
+using System.Threading.Tasks;
+using CmlLib.Core.Auth;
+using CmlLib.Core.Auth.Microsoft;
+using XboxAuthNet.Game.Msal;
+using XboxAuthNet.Game.Msal.OAuth;
+
+namespace ModpackLauncher.Services;
+
+/// <summary>
+/// Microsoft auth wrapper. Two modes:
+///   1. Custom Azure AD client ID (msalClientId set) -> MSAL flow. Requires Microsoft
+///      to have approved the app for Minecraft API access.
+///   2. No custom client ID (default) -> CmlLib's BuildDefault() which uses the
+///      WebView2-driven Microsoft Live OAuth flow with the Xbox Live SDK client ID.
+///      Doesn't require an Azure registration; works out of the box on any Win10/11
+///      machine that has the WebView2 Runtime installed (preinstalled since 2021).
+/// </summary>
+public sealed class AuthService
+{
+    private readonly string _clientId;
+
+    public AuthService(string clientId)
+    {
+        _clientId = clientId;
+    }
+
+    /// <summary>True when the user has provided their own Azure App Registration ID.</summary>
+    public bool HasCustomClientId => !string.IsNullOrWhiteSpace(_clientId)
+        && _clientId != "00000000-0000-0000-0000-000000000000";
+
+    /// <summary>Auth is always available now (BuildDefault provides a fallback).</summary>
+    public bool IsConfigured => true;
+
+    public async Task<MSession> AuthenticateAsync()
+    {
+        var loginHandler = await BuildLoginHandlerAsync();
+        try
+        {
+            return await loginHandler.AuthenticateSilently();
+        }
+        catch
+        {
+            return await loginHandler.AuthenticateInteractively();
+        }
+    }
+
+    public async Task<MSession> SignInInteractivelyAsync()
+    {
+        var loginHandler = await BuildLoginHandlerAsync();
+        return await loginHandler.AuthenticateInteractively();
+    }
+
+    public async Task<MSession?> TryAuthenticateSilentlyAsync()
+    {
+        try
+        {
+            var loginHandler = await BuildLoginHandlerAsync();
+            return await loginHandler.AuthenticateSilently();
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    public async Task SignOutAsync()
+    {
+        try
+        {
+            var loginHandler = await BuildLoginHandlerAsync();
+            await loginHandler.Signout();
+        }
+        catch
+        {
+            // best-effort
+        }
+    }
+
+    private async Task<JELoginHandler> BuildLoginHandlerAsync()
+    {
+        if (HasCustomClientId)
+        {
+            // Custom Azure AD MSAL flow -- requires the app to be approved by Microsoft.
+            var app = await MsalClientHelper.BuildApplicationWithCache(_clientId);
+            return new JELoginHandlerBuilder()
+                .WithOAuthProvider(new MsalCodeFlowProvider(app))
+                .Build();
+        }
+
+        // Default path: WebView2 + Xbox Live SDK community client ID. No Azure registration.
+        // Note: requires WebView2 Runtime on Windows (preinstalled on Win10/11 since 2021).
+        return JELoginHandlerBuilder.BuildDefault();
+    }
+}

launcher/Services/FileLog.cs

@@ -0,0 +1,45 @@
+using System;
+using System.IO;
+
+namespace ModpackLauncher.Services;
+
+public static class FileLog
+{
+    private static readonly object _lock = new();
+
+    public static string LogPath { get; } = BuildPath();
+
+    private static string BuildPath()
+    {
+        var dir = Path.Combine(
+            Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
+            "BrassAndSigil"
+        );
+        Directory.CreateDirectory(dir);
+        return Path.Combine(dir, "launcher.log");
+    }
+
+    public static void Init()
+    {
+        try
+        {
+            // Truncate per launch so we always have the most recent run.
+            File.WriteAllText(LogPath,
+                $"=== ModpackLauncher launched {DateTime.Now:yyyy-MM-dd HH:mm:ss} ==={Environment.NewLine}");
+        }
+        catch { }
+    }
+
+    public static void Write(string message)
+    {
+        try
+        {
+            lock (_lock)
+            {
+                File.AppendAllText(LogPath,
+                    $"[{DateTime.Now:HH:mm:ss}] {message}{Environment.NewLine}");
+            }
+        }
+        catch { }
+    }
+}

launcher/Services/IrisConfigService.cs

@@ -0,0 +1,65 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace ModpackLauncher.Services;
+
+/// <summary>
+/// Pre-seeds Iris's <c>config/iris.properties</c> with a default shader pack
+/// for fresh installs, so friends launch the game and the recommended shader
+/// is already on rather than them having to dig through Video Settings.
+///
+/// Respects user choice: if the file already exists with a non-empty
+/// <c>shaderPack=...</c> entry, we leave it alone -- only fresh installs (or
+/// installs where Iris has never been opened) get the default.
+/// </summary>
+public sealed class IrisConfigService
+{
+    public void SetDefaultShader(string gameDir, string shaderPackFilename)
+    {
+        if (string.IsNullOrWhiteSpace(shaderPackFilename)) return;
+        var configDir = Path.Combine(gameDir, "config");
+        Directory.CreateDirectory(configDir);
+        var path = Path.Combine(configDir, "iris.properties");
+
+        var lines = File.Exists(path) ? File.ReadAllLines(path).ToList() : new List<string>();
+
+        // If a shaderPack is already chosen and non-empty (the user picked
+        // something), respect it and bail.
+        var existingShader = lines
+            .Select(l => l.TrimStart())
+            .Where(l => l.Length > 0 && l[0] != '#')
+            .Select(l => { var i = l.IndexOf('='); return i < 0 ? null : new { Key = l.Substring(0, i).Trim(), Value = l.Substring(i + 1).Trim() }; })
+            .Where(p => p != null && p.Key.Equals("shaderPack", System.StringComparison.OrdinalIgnoreCase))
+            .Select(p => p!.Value)
+            .FirstOrDefault();
+        if (!string.IsNullOrEmpty(existingShader)) return;
+
+        // No shader set -- write our defaults. Update existing keys in-place if
+        // they exist (e.g. shaderPack="" placeholder), append otherwise.
+        var defaults = new Dictionary<string, string>(System.StringComparer.OrdinalIgnoreCase)
+        {
+            { "shaderPack", shaderPackFilename },
+            { "enableShaders", "true" },
+        };
+        var seen = new HashSet<string>(System.StringComparer.OrdinalIgnoreCase);
+        for (int i = 0; i < lines.Count; i++)
+        {
+            var trimmed = lines[i].TrimStart();
+            if (trimmed.Length == 0 || trimmed[0] == '#') continue;
+            var idx = trimmed.IndexOf('=');
+            if (idx < 0) continue;
+            var key = trimmed.Substring(0, idx).Trim();
+            if (defaults.TryGetValue(key, out var val))
+            {
+                lines[i] = $"{key}={val}";
+                seen.Add(key);
+            }
+        }
+        foreach (var (k, v) in defaults)
+        {
+            if (!seen.Contains(k)) lines.Add($"{k}={v}");
+        }
+        File.WriteAllLines(path, lines);
+    }
+}

launcher/Services/LaunchService.cs

@@ -0,0 +1,227 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Net.Http;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using CmlLib.Core;
+using CmlLib.Core.Auth;
+using CmlLib.Core.Installers;
+using CmlLib.Core.ProcessBuilder;
+using CmlLib.Core.Installer.Forge;
+using CmlLib.Core.Installer.NeoForge;
+using ModpackLauncher.Models;
+
+namespace ModpackLauncher.Services;
+
+public sealed class LaunchService
+{
+    private readonly MinecraftLauncher _launcher;
+    private readonly ForgeInstaller _forgeInstaller;
+    private readonly NeoForgeInstaller _neoForgeInstaller;
+
+    private readonly string _installDir;
+
+    public LaunchService(string installDir)
+    {
+        _installDir = installDir;
+        var path = new MinecraftPath(installDir);
+        _launcher = new MinecraftLauncher(path);
+        _forgeInstaller = new ForgeInstaller(_launcher);
+        _neoForgeInstaller = new NeoForgeInstaller(_launcher);
+    }
+
+    public MinecraftLauncher Launcher => _launcher;
+
+    /// <summary>
+    /// Belt-and-braces check after the loader installer runs: parse the version JSON
+    /// and download any libraries that are listed but missing on disk. Works around
+    /// a known CmlLib quirk where libraries with @jar suffix in the Maven coordinate
+    /// (e.g. "cpw.mods:bootstraplauncher:2.0.2@jar" used by NeoForge 21.1.x) get
+    /// skipped by the installer's library downloader.
+    /// </summary>
+    private async Task VerifyVersionLibrariesAsync(string versionId,
+                                                    IProgress<ProgressReport> progress,
+                                                    CancellationToken ct)
+    {
+        var versionJsonPath = Path.Combine(_installDir, "versions", versionId, $"{versionId}.json");
+        if (!File.Exists(versionJsonPath)) return;
+
+        using var doc = JsonDocument.Parse(await File.ReadAllTextAsync(versionJsonPath, ct).ConfigureAwait(false));
+        if (!doc.RootElement.TryGetProperty("libraries", out var libsArr)) return;
+
+        var libsDir = Path.Combine(_installDir, "libraries");
+        var missing = new System.Collections.Generic.List<(string Path, string Url, string? Sha1)>();
+
+        foreach (var lib in libsArr.EnumerateArray())
+        {
+            if (!lib.TryGetProperty("downloads", out var dls)) continue;
+            if (!dls.TryGetProperty("artifact", out var art)) continue;
+            if (!art.TryGetProperty("path", out var pPath) || !art.TryGetProperty("url", out var pUrl)) continue;
+
+            var relPath = pPath.GetString();
+            var url = pUrl.GetString();
+            var sha1 = art.TryGetProperty("sha1", out var pSha1) ? pSha1.GetString() : null;
+            if (string.IsNullOrEmpty(relPath) || string.IsNullOrEmpty(url)) continue;
+
+            var fullPath = Path.Combine(libsDir, relPath.Replace('/', Path.DirectorySeparatorChar));
+            if (!File.Exists(fullPath))
+            {
+                missing.Add((fullPath, url, sha1));
+            }
+        }
+
+        if (missing.Count == 0) return;
+
+        progress.Report(new ProgressReport(
+            ProgressKind.Status,
+            $"Verifying loader libraries: {missing.Count} missing, fetching..."));
+
+        using var http = new HttpClient();
+        http.Timeout = TimeSpan.FromMinutes(5);
+        for (int i = 0; i < missing.Count; i++)
+        {
+            ct.ThrowIfCancellationRequested();
+            var (path, url, _) = missing[i];
+            progress.Report(new ProgressReport(
+                ProgressKind.Log,
+                $"  Library {i + 1}/{missing.Count}: {Path.GetFileName(path)}"));
+            Directory.CreateDirectory(Path.GetDirectoryName(path)!);
+            var bytes = await http.GetByteArrayAsync(url, ct).ConfigureAwait(false);
+            await File.WriteAllBytesAsync(path, bytes, ct).ConfigureAwait(false);
+        }
+
+        progress.Report(new ProgressReport(
+            ProgressKind.Status,
+            "Loader libraries verified."));
+    }
+
+    public async Task<string> InstallVersionAsync(
+        Manifest manifest,
+        IProgress<ProgressReport> progress,
+        CancellationToken ct)
+    {
+        EventHandler<InstallerProgressChangedEventArgs> fileProgressHandler = (_, args) =>
+        {
+            var pct = args.TotalTasks > 0
+                ? (args.ProgressedTasks * 100.0 / args.TotalTasks)
+                : -1;
+            progress.Report(new ProgressReport(
+                ProgressKind.Progress,
+                $"{args.EventType}: {args.Name ?? ""}",
+                Current: args.ProgressedTasks,
+                Total: args.TotalTasks,
+                Percent: pct
+            ));
+        };
+
+        EventHandler<ByteProgress> byteProgressHandler = (_, args) =>
+        {
+            if (args.TotalBytes <= 0) return;
+            var pct = args.ToRatio() * 100.0;
+            progress.Report(new ProgressReport(
+                ProgressKind.Progress,
+                $"{args.ProgressedBytes:N0} / {args.TotalBytes:N0} bytes",
+                Current: (int)Math.Min(args.ProgressedBytes, int.MaxValue),
+                Total: (int)Math.Min(args.TotalBytes, int.MaxValue),
+                Percent: pct
+            ));
+        };
+
+        _launcher.FileProgressChanged += fileProgressHandler;
+        _launcher.ByteProgressChanged += byteProgressHandler;
+
+        try
+        {
+            var mcVersion = manifest.Minecraft.Version;
+            var loader = manifest.Loader;
+
+            progress.Report(new ProgressReport(ProgressKind.Status, $"Installing Minecraft {mcVersion}..."));
+            await _launcher.InstallAsync(mcVersion, ct).AsTask().ConfigureAwait(false);
+
+            if (loader == null || string.IsNullOrEmpty(loader.Type) ||
+                loader.Type.Equals("vanilla", StringComparison.OrdinalIgnoreCase))
+            {
+                return mcVersion;
+            }
+
+            if (loader.Type.Equals("forge", StringComparison.OrdinalIgnoreCase))
+            {
+                progress.Report(new ProgressReport(
+                    ProgressKind.Status,
+                    $"Installing Forge {loader.Version} for {mcVersion}..."
+                ));
+                var fid = await _forgeInstaller.Install(mcVersion, loader.Version).ConfigureAwait(false);
+                await VerifyVersionLibrariesAsync(fid, progress, ct).ConfigureAwait(false);
+                return fid;
+            }
+
+            if (loader.Type.Equals("neoforge", StringComparison.OrdinalIgnoreCase))
+            {
+                progress.Report(new ProgressReport(
+                    ProgressKind.Status,
+                    $"Installing NeoForge {loader.Version} for {mcVersion}..."
+                ));
+                var nid = await _neoForgeInstaller.Install(mcVersion, loader.Version).ConfigureAwait(false);
+                await VerifyVersionLibrariesAsync(nid, progress, ct).ConfigureAwait(false);
+                return nid;
+            }
+
+            throw new NotSupportedException(
+                $"Loader '{loader.Type}' is not yet supported. Use 'forge', 'neoforge', or 'vanilla'."
+            );
+        }
+        finally
+        {
+            _launcher.FileProgressChanged -= fileProgressHandler;
+            _launcher.ByteProgressChanged -= byteProgressHandler;
+        }
+    }
+
+    public async Task<int> LaunchAsync(
+        string versionId,
+        MSession session,
+        int minMemoryMB,
+        int maxMemoryMB,
+        IProgress<ProgressReport> progress,
+        CancellationToken ct)
+    {
+        var option = new MLaunchOption
+        {
+            Session = session,
+            MaximumRamMb = maxMemoryMB,
+            MinimumRamMb = minMemoryMB,
+            // Generational ZGC: low-pause concurrent collector -- recommended by
+            // Distant Horizons (and broadly better than the default G1 for modded MC).
+            // Requires Java 21+ which CmlLib auto-installs for MC 1.21.1.
+            ExtraJvmArguments = new[]
+            {
+                new MArgument("-XX:+UseZGC"),
+                new MArgument("-XX:+ZGenerational"),
+            }
+        };
+
+        progress.Report(new ProgressReport(ProgressKind.Status, "Building launch process..."));
+        var process = await _launcher.BuildProcessAsync(versionId, option).ConfigureAwait(false);
+
+        var wrapper = new ProcessWrapper(process);
+        wrapper.OutputReceived += (_, log) =>
+        {
+            progress.Report(new ProgressReport(ProgressKind.Log, log));
+        };
+
+        wrapper.StartWithEvents();
+        progress.Report(new ProgressReport(
+            ProgressKind.Status,
+            $"Minecraft launched (PID {process.Id})"
+        ));
+
+        var exitCode = await wrapper.WaitForExitTaskAsync().ConfigureAwait(false);
+        progress.Report(new ProgressReport(
+            ProgressKind.Status,
+            $"Game exited (code {exitCode})"
+        ));
+        return exitCode;
+    }
+}

launcher/Services/ManifestSyncService.cs

@@ -0,0 +1,252 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Net.Http;
+using System.Security.Cryptography;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using ModpackLauncher.Models;
+
+namespace ModpackLauncher.Services;
+
+public sealed class ManifestSyncService
+{
+    private const string PackVersionFile = "pack-version.json";
+
+    private static readonly string[] ManagedRoots =
+    {
+        "mods", "config", "resourcepacks", "shaderpacks", "kubejs", "defaultconfigs"
+    };
+
+    private readonly HttpClient _http;
+
+    public ManifestSyncService(HttpClient? http = null)
+    {
+        _http = http ?? new HttpClient();
+        _http.Timeout = TimeSpan.FromMinutes(5);
+    }
+
+    /// <summary>Configure HTTP Basic auth for all subsequent requests. Pass null to clear.</summary>
+    public void SetBasicAuth(string? username, string? password)
+    {
+        if (string.IsNullOrEmpty(username))
+        {
+            _http.DefaultRequestHeaders.Authorization = null;
+            return;
+        }
+        var raw = $"{username}:{password ?? ""}";
+        var b64 = Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(raw));
+        _http.DefaultRequestHeaders.Authorization =
+            new System.Net.Http.Headers.AuthenticationHeaderValue("Basic", b64);
+    }
+
+    public sealed record SyncResult(Manifest Manifest, int Downloaded, int Removed);
+
+    /// <summary>Just fetch the manifest JSON without doing the full file sync. Used for "is an update available?" checks on startup.</summary>
+    public async Task<Manifest> FetchManifestOnlyAsync(string manifestUrl, CancellationToken ct = default)
+    {
+        var json = await _http.GetStringAsync(manifestUrl, ct).ConfigureAwait(false);
+        var manifest = JsonSerializer.Deserialize<Manifest>(json, new JsonSerializerOptions
+        {
+            PropertyNameCaseInsensitive = true
+        });
+        if (manifest == null) throw new InvalidOperationException("Manifest is empty or invalid.");
+        manifest.Files ??= new System.Collections.Generic.List<ManifestFile>();
+        return manifest;
+    }
+
+    /// <summary>
+    /// Fast check (no hashing): which files listed in the manifest are missing on disk.
+    /// Used as a pre-launch sanity pass to catch AV quarantines / interrupted installs.
+    /// </summary>
+    public System.Collections.Generic.List<ManifestFile> FindMissingFiles(Manifest manifest, string installDir)
+    {
+        var missing = new System.Collections.Generic.List<ManifestFile>();
+        foreach (var file in manifest.Files)
+        {
+            var dest = Path.Combine(installDir, file.Path);
+            if (!File.Exists(dest)) missing.Add(file);
+        }
+        return missing;
+    }
+
+    public PackVersionRecord? GetLocalPackVersion(string installDir)
+    {
+        var path = Path.Combine(installDir, PackVersionFile);
+        if (!File.Exists(path)) return null;
+        try
+        {
+            return JsonSerializer.Deserialize<PackVersionRecord>(File.ReadAllText(path));
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    public async Task<SyncResult> SyncAsync(
+        string manifestUrl,
+        string installDir,
+        IProgress<ProgressReport> progress,
+        CancellationToken ct = default)
+    {
+        progress.Report(new ProgressReport(ProgressKind.Status, "Fetching manifest..."));
+
+        var manifestJson = await _http.GetStringAsync(manifestUrl, ct).ConfigureAwait(false);
+        var manifest = JsonSerializer.Deserialize<Manifest>(manifestJson, new JsonSerializerOptions
+        {
+            PropertyNameCaseInsensitive = true
+        }) ?? throw new InvalidOperationException("Manifest is empty or invalid.");
+
+        if (string.IsNullOrWhiteSpace(manifest.Minecraft.Version))
+        {
+            throw new InvalidOperationException("Manifest is missing minecraft.version.");
+        }
+
+        Directory.CreateDirectory(installDir);
+
+        var local = GetLocalPackVersion(installDir);
+        progress.Report(new ProgressReport(
+            ProgressKind.Status,
+            $"Pack: {manifest.Name ?? "modpack"} v{manifest.Version ?? "?"} (local: {local?.Version ?? "none"})"
+        ));
+
+        var wantedPaths = new HashSet<string>(
+            manifest.Files.Select(f => NormalizePath(f.Path)),
+            StringComparer.OrdinalIgnoreCase
+        );
+
+        // Remove managed files no longer in manifest
+        var toRemove = new List<string>();
+        foreach (var root in ManagedRoots)
+        {
+            var rootDir = Path.Combine(installDir, root);
+            if (!Directory.Exists(rootDir)) continue;
+            foreach (var file in Directory.EnumerateFiles(rootDir, "*", SearchOption.AllDirectories))
+            {
+                var rel = NormalizePath(Path.GetRelativePath(installDir, file));
+                if (!wantedPaths.Contains(rel))
+                {
+                    toRemove.Add(file);
+                }
+            }
+        }
+
+        foreach (var file in toRemove)
+        {
+            try
+            {
+                File.Delete(file);
+                progress.Report(new ProgressReport(
+                    ProgressKind.Log,
+                    $"Removed: {Path.GetRelativePath(installDir, file)}"
+                ));
+            }
+            catch (Exception ex)
+            {
+                progress.Report(new ProgressReport(
+                    ProgressKind.Log,
+                    $"Could not remove {file}: {ex.Message}"
+                ));
+            }
+        }
+
+        // Determine what to download
+        var toDownload = new List<ManifestFile>();
+        foreach (var file in manifest.Files)
+        {
+            ct.ThrowIfCancellationRequested();
+            var dest = Path.Combine(installDir, file.Path);
+            if (!File.Exists(dest))
+            {
+                toDownload.Add(file);
+                continue;
+            }
+            if (!string.IsNullOrEmpty(file.Sha1))
+            {
+                var actual = await ComputeSha1Async(dest, ct).ConfigureAwait(false);
+                if (!string.Equals(actual, file.Sha1, StringComparison.OrdinalIgnoreCase))
+                {
+                    toDownload.Add(file);
+                }
+            }
+        }
+
+        progress.Report(new ProgressReport(
+            ProgressKind.Status,
+            toDownload.Count == 0 ? "Already up-to-date." : $"Downloading {toDownload.Count} file(s)..."
+        ));
+
+        for (int i = 0; i < toDownload.Count; i++)
+        {
+            ct.ThrowIfCancellationRequested();
+            var file = toDownload[i];
+            var pct = toDownload.Count == 0 ? 100 : (i * 100.0 / toDownload.Count);
+            progress.Report(new ProgressReport(
+                ProgressKind.Progress,
+                $"Downloading {file.Path}",
+                Current: i + 1,
+                Total: toDownload.Count,
+                Percent: pct
+            ));
+            var dest = Path.Combine(installDir, file.Path);
+            await DownloadFileAsync(file.Url, dest, file.Sha1, ct).ConfigureAwait(false);
+        }
+
+        var record = new PackVersionRecord
+        {
+            Name = manifest.Name,
+            Version = manifest.Version,
+            SyncedAt = DateTime.UtcNow.ToString("o")
+        };
+        await File.WriteAllTextAsync(
+            Path.Combine(installDir, PackVersionFile),
+            JsonSerializer.Serialize(record, new JsonSerializerOptions { WriteIndented = true }),
+            ct
+        ).ConfigureAwait(false);
+
+        progress.Report(new ProgressReport(ProgressKind.Status, "Sync complete."));
+        return new SyncResult(manifest, toDownload.Count, toRemove.Count);
+    }
+
+    private async Task DownloadFileAsync(string url, string destPath, string? expectedSha1, CancellationToken ct)
+    {
+        Directory.CreateDirectory(Path.GetDirectoryName(destPath)!);
+        var tmp = destPath + ".part";
+
+        using (var response = await _http.GetAsync(url, HttpCompletionOption.ResponseHeadersRead, ct).ConfigureAwait(false))
+        {
+            response.EnsureSuccessStatusCode();
+            await using var src = await response.Content.ReadAsStreamAsync(ct).ConfigureAwait(false);
+            await using var dst = File.Create(tmp);
+            await src.CopyToAsync(dst, ct).ConfigureAwait(false);
+        }
+
+        if (!string.IsNullOrEmpty(expectedSha1))
+        {
+            var actual = await ComputeSha1Async(tmp, ct).ConfigureAwait(false);
+            if (!string.Equals(actual, expectedSha1, StringComparison.OrdinalIgnoreCase))
+            {
+                File.Delete(tmp);
+                throw new InvalidOperationException(
+                    $"Hash mismatch for {Path.GetFileName(destPath)} (expected {expectedSha1}, got {actual})"
+                );
+            }
+        }
+
+        if (File.Exists(destPath)) File.Delete(destPath);
+        File.Move(tmp, destPath);
+    }
+
+    private static async Task<string> ComputeSha1Async(string path, CancellationToken ct)
+    {
+        using var sha = SHA1.Create();
+        await using var stream = File.OpenRead(path);
+        var bytes = await sha.ComputeHashAsync(stream, ct).ConfigureAwait(false);
+        return Convert.ToHexString(bytes).ToLowerInvariant();
+    }
+
+    private static string NormalizePath(string p) => p.Replace('\\', '/').TrimStart('/');
+}

launcher/Services/ProgressReport.cs

@@ -0,0 +1,17 @@
+namespace ModpackLauncher.Services;
+
+public enum ProgressKind
+{
+    Status,
+    Progress,
+    Log,
+    Error
+}
+
+public sealed record ProgressReport(
+    ProgressKind Kind,
+    string Message,
+    int Current = 0,
+    int Total = 0,
+    double Percent = -1
+);

launcher/Services/ServerListService.cs

@@ -0,0 +1,101 @@
+using System;
+using System.IO;
+using System.Linq;
+using fNbt;
+
+namespace ModpackLauncher.Services;
+
+/// <summary>
+/// Pre-populates Minecraft's multiplayer server list (`servers.dat`) so the
+/// modpack's server is one click away on first launch.
+///
+/// servers.dat is uncompressed NBT (unlike level.dat which is gzipped). Schema:
+///   compound {
+///     servers : list[compound] {
+///       name             : string
+///       ip               : string
+///       acceptTextures   : byte (optional, 1 = enabled)
+///       hidden           : byte (optional, 0 = visible)
+///       icon             : string (optional, base64 PNG)
+///     }
+///   }
+/// </summary>
+public sealed class ServerListService
+{
+    /// <summary>
+    /// Add or update an entry. Match-by-IP: if an entry with the same IP exists,
+    /// update its name; otherwise prepend a new entry so the friend's first
+    /// glance at multiplayer shows our server at the top.
+    /// </summary>
+    public void EnsureServer(string gameDir, string name, string ip)
+    {
+        if (string.IsNullOrWhiteSpace(name) || string.IsNullOrWhiteSpace(ip)) return;
+        Directory.CreateDirectory(gameDir);
+        var path = Path.Combine(gameDir, "servers.dat");
+
+        NbtCompound root;
+        NbtList servers;
+
+        if (File.Exists(path))
+        {
+            try
+            {
+                var nbt = new NbtFile();
+                nbt.LoadFromFile(path, NbtCompression.None, _ => true);
+                root = nbt.RootTag;
+                if (root.TryGet("servers", out NbtList? existingList) && existingList is not null)
+                {
+                    servers = existingList;
+                }
+                else
+                {
+                    servers = new NbtList("servers", NbtTagType.Compound);
+                    root.Add(servers);
+                }
+            }
+            catch
+            {
+                // Existing file unreadable -- start fresh rather than crashing the install.
+                root = new NbtCompound("");
+                servers = new NbtList("servers", NbtTagType.Compound);
+                root.Add(servers);
+            }
+        }
+        else
+        {
+            root = new NbtCompound("");
+            servers = new NbtList("servers", NbtTagType.Compound);
+            root.Add(servers);
+        }
+
+        // Match-by-IP. If found, update the display name; otherwise prepend.
+        for (int i = 0; i < servers.Count; i++)
+        {
+            if (servers[i] is not NbtCompound entry) continue;
+            if (entry.TryGet("ip", out NbtString? ipTag) && ipTag?.Value == ip)
+            {
+                entry["name"] = new NbtString("name", name);
+                Save(root, path);
+                return;
+            }
+        }
+
+        var newEntry = new NbtCompound
+        {
+            new NbtString("name", name),
+            new NbtString("ip", ip),
+            // acceptTextures = 1 lets the server send its resource pack without prompting
+            // (the player still gets the prompt; this just allows the option). Default
+            // value matches what vanilla MC writes when you click "Done" in the UI.
+            new NbtByte("acceptTextures", 1),
+        };
+        servers.Insert(0, newEntry);
+        Save(root, path);
+    }
+
+    private static void Save(NbtCompound root, string path)
+    {
+        var file = new NbtFile(root);
+        file.SaveToFile(path, NbtCompression.None);
+    }
+}

launcher/Services/SystemInfo.cs

@@ -0,0 +1,67 @@
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+
+namespace ModpackLauncher.Services;
+
+public static class SystemInfo
+{
+    private const long DefaultFallbackKB = 8L * 1024 * 1024; // assume 8 GB if detection fails
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool GetPhysicallyInstalledSystemMemory(out long memoryInKilobytes);
+
+    /// <summary>Total physically installed system RAM in megabytes.</summary>
+    public static int TotalPhysicalMemoryMB
+    {
+        get
+        {
+            try
+            {
+                if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                {
+                    if (GetPhysicallyInstalledSystemMemory(out var kb))
+                        return (int)(kb / 1024);
+                }
+                else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+                {
+                    // Read MemTotal from /proc/meminfo
+                    foreach (var line in File.ReadAllLines("/proc/meminfo"))
+                    {
+                        if (line.StartsWith("MemTotal:", StringComparison.Ordinal))
+                        {
+                            var parts = line.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+                            if (parts.Length >= 2 && long.TryParse(parts[1], out var memKb))
+                                return (int)(memKb / 1024);
+                        }
+                    }
+                }
+                else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+                {
+                    // GC heap-size hint; not perfect but a reasonable fallback for macOS.
+                    var gcInfo = GC.GetGCMemoryInfo();
+                    if (gcInfo.TotalAvailableMemoryBytes > 0)
+                        return (int)(gcInfo.TotalAvailableMemoryBytes / (1024 * 1024));
+                }
+            }
+            catch
+            {
+                // Fall through to default
+            }
+            return (int)(DefaultFallbackKB / 1024);
+        }
+    }
+
+    /// <summary>Recommended max user-allocatable RAM (leaves headroom for OS + other apps).</summary>
+    public static int SafeMaxAllocationMB
+    {
+        get
+        {
+            var total = TotalPhysicalMemoryMB;
+            // Leave at least 4 GB for OS + browser + Discord + everything else.
+            var headroom = total >= 32 * 1024 ? 6 * 1024 : 4 * 1024;
+            return Math.Max(2048, total - headroom);
+        }
+    }
+}

launcher/Services/WebView2Check.cs

@@ -0,0 +1,39 @@
+using System;
+using Microsoft.Win32;
+
+namespace ModpackLauncher.Services;
+
+/// <summary>
+/// Detects whether Microsoft Edge WebView2 Runtime is installed.
+/// Required by the Xbox Live SDK + WebView2 sign-in flow used by the launcher when
+/// no custom Azure client ID is configured. Preinstalled on Windows 10/11 since
+/// 2021 (came with Edge), but not guaranteed on older / cleaned Windows installs.
+/// </summary>
+public static class WebView2Check
+{
+    private const string ClientGuid = "{F3017226-FE2A-4295-8BDF-00C3A9A7E4C5}"; // Microsoft Edge WebView2 Runtime
+
+    public const string DownloadUrl = "https://developer.microsoft.com/microsoft-edge/webview2/";
+
+    public static bool IsInstalled()
+    {
+        // The runtime registers in one of three places depending on machine vs. per-user install.
+        return GetVersion(RegistryHive.LocalMachine, $@"SOFTWARE\WOW6432Node\Microsoft\EdgeUpdate\Clients\{ClientGuid}") is { } v1 && v1 != "0.0.0.0"
+            || GetVersion(RegistryHive.LocalMachine, $@"SOFTWARE\Microsoft\EdgeUpdate\Clients\{ClientGuid}")            is { } v2 && v2 != "0.0.0.0"
+            || GetVersion(RegistryHive.CurrentUser,  $@"Software\Microsoft\EdgeUpdate\Clients\{ClientGuid}")            is { } v3 && v3 != "0.0.0.0";
+    }
+
+    private static string? GetVersion(RegistryHive hive, string keyPath)
+    {
+        try
+        {
+            using var baseKey = RegistryKey.OpenBaseKey(hive, RegistryView.Default);
+            using var key = baseKey.OpenSubKey(keyPath);
+            return key?.GetValue("pv") as string;
+        }
+        catch
+        {
+            return null;
+        }
+    }
+}

launcher/Services/WhitelistRequestService.cs

@@ -0,0 +1,67 @@
+using System;
+using System.Net.Http;
+using System.Net.Http.Json;
+using System.Text.Json.Serialization;
+using System.Threading.Tasks;
+
+namespace ModpackLauncher.Services;
+
+/// <summary>
+/// Friend-side wrapper for the brass-sigil-server's public whitelist endpoints.
+/// Exists so the launcher can:
+///   - Send a "please add me" request without the friend needing to share their
+///     MC username with the admin out-of-band.
+///   - Poll status afterwards so the launcher UI reflects pending/approved/denied.
+/// </summary>
+public sealed class WhitelistRequestService
+{
+    private static readonly HttpClient _http = new() { Timeout = TimeSpan.FromSeconds(10) };
+
+    public sealed class StatusResponse
+    {
+        [JsonPropertyName("ok")]     public bool Ok { get; set; }
+        [JsonPropertyName("status")] public string? Status { get; set; }
+    }
+
+    public sealed class RequestResponse
+    {
+        [JsonPropertyName("ok")]     public bool Ok { get; set; }
+        [JsonPropertyName("status")] public string? Status { get; set; }
+        [JsonPropertyName("error")]  public string? Error { get; set; }
+    }
+
+    /// <summary>
+    /// Returns "pending" / "approved" / "denied" / "unknown" / "" (network error).
+    /// </summary>
+    public async Task<string> GetStatusAsync(string panelUrl, string username)
+    {
+        try
+        {
+            var url = $"{panelUrl.TrimEnd('/')}/api/whitelist/status?username={Uri.EscapeDataString(username)}";
+            var resp = await _http.GetFromJsonAsync<StatusResponse>(url);
+            return resp?.Status ?? "";
+        }
+        catch
+        {
+            return "";
+        }
+    }
+
+    public async Task<RequestResponse> SubmitAsync(string panelUrl, string username, string? message = null)
+    {
+        try
+        {
+            var url = $"{panelUrl.TrimEnd('/')}/api/whitelist/request";
+            var resp = await _http.PostAsJsonAsync(url, new { username, message });
+            var body = await resp.Content.ReadFromJsonAsync<RequestResponse>();
+            if (body is null) return new RequestResponse { Ok = false, Error = "Empty response." };
+            if (!resp.IsSuccessStatusCode && string.IsNullOrEmpty(body.Error))
+                body.Error = $"HTTP {(int)resp.StatusCode}";
+            return body;
+        }
+        catch (Exception ex)
+        {
+            return new RequestResponse { Ok = false, Error = ex.Message };
+        }
+    }
+}

launcher/app.manifest

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <!-- This manifest is used on Windows only.
+       Don't remove it as it might cause problems with window transparency and embedded controls.
+       For more details visit https://learn.microsoft.com/en-us/windows/win32/sbscs/application-manifests -->
+  <assemblyIdentity version="1.0.0.0" name="ModpackLauncher.Desktop"/>
+
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- A list of the Windows versions that this application has been tested on
+           and is designed to work with. Uncomment the appropriate elements
+           and Windows will automatically select the most compatible environment. -->
+
+      <!-- Windows 10 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
+    </application>
+  </compatibility>
+</assembly>

launcher/launcher-config.template.json

@@ -0,0 +1,10 @@
+{
+  "_comment": "Copy this file to launcher-config.json and fill in real values before building. The launcher-config.json file is gitignored so local values never get committed. httpUsername/httpPassword are optional and only needed if your manifest/file host uses HTTP Basic auth.",
+  "packName": "Brass & Sigil",
+  "manifestUrl": "https://your-server.example/pack/manifest.json",
+  "installDirName": "BrassAndSigilData",
+  "memoryMB": 8192,
+  "msalClientId": "00000000-0000-0000-0000-000000000000",
+  "httpUsername": null,
+  "httpPassword": null
+}

launcher/manifest.example.json

@@ -0,0 +1,33 @@
+{
+  "name": "Brass & Sigil",
+  "version": "0.1.0",
+  "minecraft": {
+    "version": "1.21.1"
+  },
+  "loader": {
+    "type": "neoforge",
+    "version": "21.1.95"
+  },
+  "files": [
+    {
+      "path": "mods/create-1.21.1-6.0.10.jar",
+      "url": "https://sijbers.uk/pack/files/mods/create-1.21.1-6.0.10.jar",
+      "sha1": "0e97e49837bed766e6f28a4c95b04885d6acc353"
+    },
+    {
+      "path": "mods/create-aeronautics-bundled-1.21.1-1.2.1.jar",
+      "url": "https://sijbers.uk/pack/files/mods/create-aeronautics-bundled-1.21.1-1.2.1.jar",
+      "sha1": "fdf1ae69e8b6437e0196b3a35dd2325aa904aba9"
+    },
+    {
+      "path": "mods/distant-horizons-3.0.2-b-1.21.1.jar",
+      "url": "https://sijbers.uk/pack/files/mods/distant-horizons-3.0.2-b-1.21.1.jar",
+      "sha1": "0000000000000000000000000000000000000000"
+    },
+    {
+      "path": "config/example.cfg",
+      "url": "https://sijbers.uk/pack/files/config/example.cfg",
+      "sha1": "0000000000000000000000000000000000000000"
+    }
+  ]
+}

pack/pack.lock.json

@@ -0,0 +1,349 @@
+{
+    "$schema":  "Brass-and-Sigil pack.lock.json - generated, do not edit by hand unless you know what you are doing",
+    "name":  "Brass and Sigil",
+    "version":  "0.9.2",
+    "minecraft":  "1.21.1",
+    "loader":  {
+                   "type":  "neoforge",
+                   "version":  "21.1.228"
+               },
+    "lockedAt":  "2026-05-04T14:22:58.7131203+01:00",
+    "mods":  [
+                 {
+                     "source":  "modrinth",
+                     "slug":  "create",
+                     "versionId":  "UjX6dr61",
+                     "version":  "6.0.10+mc1.21.1",
+                     "path":  "mods/create-1.21.1-6.0.10.jar",
+                     "url":  "https://cdn.modrinth.com/data/LNytGWDc/versions/UjX6dr61/create-1.21.1-6.0.10.jar",
+                     "sha1":  "0e97e49837bed766e6f28a4c95b04885d6acc353",
+                     "size":  19123767
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "create-aeronautics",
+                     "versionId":  "YhZLrAFC",
+                     "version":  "1.2.1+mc1.21.1",
+                     "path":  "mods/create-aeronautics-bundled-1.21.1-1.2.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/oWaK0Q19/versions/YhZLrAFC/create-aeronautics-bundled-1.21.1-1.2.1.jar",
+                     "sha1":  "fdf1ae69e8b6437e0196b3a35dd2325aa904aba9",
+                     "size":  33030286
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "sable",
+                     "versionId":  "3FMsUjO4",
+                     "version":  "1.2.2+mc1.21.1",
+                     "path":  "mods/sable-neoforge-1.21.1-1.2.2.jar",
+                     "url":  "https://cdn.modrinth.com/data/T9PomCSv/versions/3FMsUjO4/sable-neoforge-1.21.1-1.2.2.jar",
+                     "sha1":  "c5ecd3fcf60a31d84112c708abe29e341b2d1b73",
+                     "size":  12719293
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "create-big-cannons",
+                     "versionId":  "bsGaXKEd",
+                     "version":  "5.11.3",
+                     "path":  "mods/createbigcannons-5.11.3+mc.1.21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/GWp4jCJj/versions/bsGaXKEd/createbigcannons-5.11.3%2Bmc.1.21.1.jar",
+                     "sha1":  "8b61fa850e260bdeb5d360576123f98c260afa50",
+                     "size":  3715787
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "create-tfmg",
+                     "versionId":  "uDi14nbt",
+                     "version":  "1.2.0",
+                     "path":  "mods/tfmg-1.2.0.jar",
+                     "url":  "https://cdn.modrinth.com/data/USgVjXsk/versions/uDi14nbt/tfmg-1.2.0.jar",
+                     "sha1":  "b520f3687f60a69eb265ff5b9a16759b9e124103",
+                     "size":  4924243
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "distanthorizons",
+                     "versionId":  "KkaaQtTD",
+                     "version":  "3.0.2-b-1.21.1",
+                     "path":  "mods/DistantHorizons-3.0.2-b-1.21.1-fabric-neoforge.jar",
+                     "url":  "https://cdn.modrinth.com/data/uCdwusMi/versions/KkaaQtTD/DistantHorizons-3.0.2-b-1.21.1-fabric-neoforge.jar",
+                     "sha1":  "1ff0a8920e52add541471f7b32d0d389997145ba",
+                     "size":  30019727
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "sodium",
+                     "versionId":  "Pb3OXVqC",
+                     "version":  "mc1.21.1-0.6.13-neoforge",
+                     "path":  "mods/sodium-neoforge-0.6.13+mc1.21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/AANobbMI/versions/Pb3OXVqC/sodium-neoforge-0.6.13%2Bmc1.21.1.jar",
+                     "sha1":  "38af70fa4dc4b2aaac636e92fdba3bedd5a025e1",
+                     "size":  1162994
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "iris",
+                     "versionId":  "t3ruzodq",
+                     "version":  "1.8.12+1.21.1-neoforge",
+                     "path":  "mods/iris-neoforge-1.8.12+mc1.21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/YL57xq9U/versions/t3ruzodq/iris-neoforge-1.8.12%2Bmc1.21.1.jar",
+                     "sha1":  "a3e6355915c7d3b2bc392724795113e51d289378",
+                     "size":  2438548
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "modernfix",
+                     "versionId":  "6U8JVjdw",
+                     "version":  "5.27.4+mc1.21.1",
+                     "path":  "mods/modernfix-neoforge-5.27.4+mc1.21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/nmDcB62a/versions/6U8JVjdw/modernfix-neoforge-5.27.4%2Bmc1.21.1.jar",
+                     "sha1":  "2f39363f0d6d5a5ccc2a9e0f50ad3385611c3cb7",
+                     "size":  562051
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "ferrite-core",
+                     "versionId":  "x7kQWVju",
+                     "version":  "7.0.3-neoforge",
+                     "path":  "mods/ferritecore-7.0.3-neoforge.jar",
+                     "url":  "https://cdn.modrinth.com/data/uXXizFIs/versions/x7kQWVju/ferritecore-7.0.3-neoforge.jar",
+                     "sha1":  "9563692efb708b6b568df27a01ec52f6311928ef",
+                     "size":  121559
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "architectury-api",
+                     "versionId":  "ZxYGwlk0",
+                     "version":  "13.0.8+neoforge",
+                     "path":  "mods/architectury-13.0.8-neoforge.jar",
+                     "url":  "https://cdn.modrinth.com/data/lhGA9TYQ/versions/ZxYGwlk0/architectury-13.0.8-neoforge.jar",
+                     "sha1":  "6ca11d3cc136bf69bb8f4d56982481eb85b5100b",
+                     "size":  584004
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "rhino",
+                     "versionId":  "ZdLtebKH",
+                     "version":  "2101.2.7-build.81+Rhino-1.21",
+                     "path":  "mods/rhino-2101.2.7-build.81.jar",
+                     "url":  "https://cdn.modrinth.com/data/sk9knFPE/versions/ZdLtebKH/rhino-2101.2.7-build.81.jar",
+                     "sha1":  "480235a9f7749f68ce6fec3b9c3cac3428b92a4a",
+                     "size":  882033
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "rpl",
+                     "versionId":  "hZ6B2Z0x",
+                     "version":  "2.1.2",
+                     "path":  "mods/ritchiesprojectilelib-2.1.2+mc.1.21.1-neoforge.jar",
+                     "url":  "https://cdn.modrinth.com/data/B3pb093D/versions/hZ6B2Z0x/ritchiesprojectilelib-2.1.2%2Bmc.1.21.1-neoforge.jar",
+                     "sha1":  "ec2e4996f8bee8714173e603e379fef8a6901765",
+                     "size":  76369
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "kubejs",
+                     "versionId":  "Fe9CjPws",
+                     "version":  "2101.7.2-build.363",
+                     "path":  "mods/kubejs-neoforge-2101.7.2-build.363.jar",
+                     "url":  "https://cdn.modrinth.com/data/umyGl7zF/versions/Fe9CjPws/kubejs-neoforge-2101.7.2-build.363.jar",
+                     "sha1":  "d4e88254e8c26687d4c6aeb4dfa9c2ad70f260a2",
+                     "size":  2270442
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "jei",
+                     "versionId":  "YAcQ6elZ",
+                     "version":  "19.27.0.340",
+                     "path":  "mods/jei-1.21.1-neoforge-19.27.0.340.jar",
+                     "url":  "https://cdn.modrinth.com/data/u6dRKJwZ/versions/YAcQ6elZ/jei-1.21.1-neoforge-19.27.0.340.jar",
+                     "sha1":  "27d0d85e7e32e926fc3664ab6815df5cdabb7941",
+                     "size":  1529391
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "jade",
+                     "versionId":  "yd8FKCmx",
+                     "version":  "15.10.5+neoforge",
+                     "path":  "mods/Jade-1.21.1-NeoForge-15.10.5.jar",
+                     "url":  "https://cdn.modrinth.com/data/nvQzSEkH/versions/yd8FKCmx/Jade-1.21.1-NeoForge-15.10.5.jar",
+                     "sha1":  "d5bf134b3dbde9f5258666823900e21341dc0a50",
+                     "size":  725742
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "chunky",
+                     "versionId":  "LuFhm4eU",
+                     "version":  "1.4.23",
+                     "path":  "mods/Chunky-NeoForge-1.4.23.jar",
+                     "url":  "https://cdn.modrinth.com/data/fALzjamp/versions/LuFhm4eU/Chunky-NeoForge-1.4.23.jar",
+                     "sha1":  "ab0c74743a653020fe2dfc4986b43e893947f3e9",
+                     "size":  340572
+                 },
+                 {
+                     "source":  "curseforge",
+                     "slug":  "ftb-library",
+                     "fileId":  "7746959",
+                     "version":  "2101.1.31",
+                     "path":  "mods/ftb-library-neoforge-2101.1.31.jar",
+                     "url":  "https://mediafilez.forgecdn.net/files/7746/959/ftb-library-neoforge-2101.1.31.jar",
+                     "sha1":  "686d4e784c28c14f7760cc22b2de6a8573b56b74",
+                     "size":  1411181
+                 },
+                 {
+                     "source":  "curseforge",
+                     "slug":  "ftb-teams",
+                     "fileId":  "7369021",
+                     "version":  "2101.1.9",
+                     "path":  "mods/ftb-teams-neoforge-2101.1.9.jar",
+                     "url":  "https://mediafilez.forgecdn.net/files/7369/21/ftb-teams-neoforge-2101.1.9.jar",
+                     "sha1":  "328e04bf1a445870aacea8fe7637670f84272a8f",
+                     "size":  291847
+                 },
+                 {
+                     "source":  "curseforge",
+                     "slug":  "ftb-chunks",
+                     "fileId":  "7608681",
+                     "version":  "2101.1.14",
+                     "path":  "mods/ftb-chunks-neoforge-2101.1.14.jar",
+                     "url":  "https://mediafilez.forgecdn.net/files/7608/681/ftb-chunks-neoforge-2101.1.14.jar",
+                     "sha1":  "908b63b11d0e00ae6c9557d3fe6440bdbcf21bb7",
+                     "size":  642340
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "ars-nouveau",
+                     "versionId":  "BmGGrC9A",
+                     "version":  "5.11.3+mc1.21.1",
+                     "path":  "mods/ars_nouveau-1.21.1-5.11.3.jar",
+                     "url":  "https://cdn.modrinth.com/data/TKB6INcv/versions/BmGGrC9A/ars_nouveau-1.21.1-5.11.3.jar",
+                     "sha1":  "0af12dd7fda63a4261ceb302c9bb57fc235641c6",
+                     "size":  20689115
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "terralith",
+                     "versionId":  "MuJMtPGQ",
+                     "version":  "2.5.8",
+                     "path":  "mods/Terralith_1.21.x_v2.5.8.jar",
+                     "url":  "https://cdn.modrinth.com/data/8oi3bsk5/versions/MuJMtPGQ/Terralith_1.21.x_v2.5.8.jar",
+                     "sha1":  "bee0cfb1a8cd4bf3d96bccea224fb45d74de9085",
+                     "size":  3115385
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "yungs-better-strongholds",
+                     "versionId":  "8U0dIfSM",
+                     "version":  "1.21.1-NeoForge-5.1.3",
+                     "path":  "mods/YungsBetterStrongholds-1.21.1-NeoForge-5.1.3.jar",
+                     "url":  "https://cdn.modrinth.com/data/kidLKymU/versions/8U0dIfSM/YungsBetterStrongholds-1.21.1-NeoForge-5.1.3.jar",
+                     "sha1":  "5d06a5850af7c577612d4592706a8e156bbe1cbf",
+                     "size":  461244
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "lithostitched",
+                     "versionId":  "IONexlgI",
+                     "version":  "1.7.2-neoforge-21.1",
+                     "path":  "mods/lithostitched-1.7.2-neoforge-21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/XaDC71GB/versions/IONexlgI/lithostitched-1.7.2-neoforge-21.1.jar",
+                     "sha1":  "ce35206214647131ebdf14212d1986349aeba79a",
+                     "size":  810015
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "c2me-neoforge",
+                     "versionId":  "9iPiN34N",
+                     "version":  "0.3.0+alpha.0.91+1.21.1",
+                     "path":  "mods/c2me-neoforge-mc1.21.1-0.3.0+alpha.0.91.jar",
+                     "url":  "https://cdn.modrinth.com/data/COlSi5iR/versions/9iPiN34N/c2me-neoforge-mc1.21.1-0.3.0%2Balpha.0.91.jar",
+                     "sha1":  "c858c8becfb5205eb12aaf0420eb82c307c2e6a7",
+                     "size":  4508649
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "noisium",
+                     "versionId":  "nJBE6tif",
+                     "version":  "2.3.0+mc1.21-1.21.1",
+                     "path":  "mods/noisium-neoforge-2.3.0+mc1.21-1.21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/KuNKN7d2/versions/nJBE6tif/noisium-neoforge-2.3.0%2Bmc1.21-1.21.1.jar",
+                     "sha1":  "1bea6b61378ba80f038256c4345d9ff3b67928c4",
+                     "size":  60296
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "async-locator-refined",
+                     "versionId":  "3BdGHbV2",
+                     "version":  "1.21.1-1.5.3",
+                     "path":  "mods/async-locator-refined-neoforge-1.21.1-1.5.3.jar",
+                     "url":  "https://cdn.modrinth.com/data/LUIHK4LD/versions/3BdGHbV2/async-locator-refined-neoforge-1.21.1-1.5.3.jar",
+                     "sha1":  "2993e3efc6d211ad8d4db179851dea6fdfff4e07",
+                     "size":  273320
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "servercore",
+                     "versionId":  "77MAnmOn",
+                     "version":  "1.5.10+1.21.1",
+                     "path":  "mods/servercore-neoforge-1.5.10+1.21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/4WWQxlQP/versions/77MAnmOn/servercore-neoforge-1.5.10%2B1.21.1.jar",
+                     "sha1":  "4524cd40cfa5019d8b5fbcb628b1616031838a0c",
+                     "size":  1429522
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "lithium",
+                     "versionId":  "RXHf27Wv",
+                     "version":  "mc1.21.1-0.15.3-neoforge",
+                     "path":  "mods/lithium-neoforge-0.15.3+mc1.21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/gvQqBUqZ/versions/RXHf27Wv/lithium-neoforge-0.15.3%2Bmc1.21.1.jar",
+                     "sha1":  "9fd5fa9076044180ae7f51672de74669196ec72e",
+                     "size":  774148
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "geckolib",
+                     "versionId":  "gFmrC8Ru",
+                     "version":  "4.8.4",
+                     "path":  "mods/geckolib-neoforge-1.21.1-4.8.4.jar",
+                     "url":  "https://cdn.modrinth.com/data/8BmcQJ2H/versions/gFmrC8Ru/geckolib-neoforge-1.21.1-4.8.4.jar",
+                     "sha1":  "eb854c8ec53ef922a5f3877a1aa4c1ce1352e0ce",
+                     "size":  622582
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "curios",
+                     "versionId":  "yohfFbgD",
+                     "version":  "9.5.1+1.21.1",
+                     "path":  "mods/curios-neoforge-9.5.1+1.21.1.jar",
+                     "url":  "https://cdn.modrinth.com/data/vvuO3ImH/versions/yohfFbgD/curios-neoforge-9.5.1%2B1.21.1.jar",
+                     "sha1":  "418fcd42e3a7844c9bdc71c9b6401fdb3894e0c4",
+                     "size":  410690
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "yungs-api",
+                     "versionId":  "ZB22DE9q",
+                     "version":  "1.21.1-NeoForge-5.1.6",
+                     "path":  "mods/YungsApi-1.21.1-NeoForge-5.1.6.jar",
+                     "url":  "https://cdn.modrinth.com/data/Ua7DFN59/versions/ZB22DE9q/YungsApi-1.21.1-NeoForge-5.1.6.jar",
+                     "sha1":  "e1c394779fb9e038e4f7a1b4558d0432607d263b",
+                     "size":  388678
+                 },
+                 {
+                     "source":  "modrinth",
+                     "slug":  "complementary-reimagined",
+                     "versionId":  "836bPNGo",
+                     "version":  "r5.7.1",
+                     "path":  "shaderpacks/ComplementaryReimagined_r5.7.1.zip",
+                     "url":  "https://cdn.modrinth.com/data/HVnmMxH1/versions/836bPNGo/ComplementaryReimagined_r5.7.1.zip",
+                     "sha1":  "b560f646a124d5204b1fb7321fec373b9c346fa5",
+                     "size":  522970
+                 }
+             ],
+    "defaultServer":  {
+                          "name":  "Brass and Sigil",
+                          "ip":  "bns.sijbers.uk"
+                      },
+    "defaultShader":  "ComplementaryReimagined_r5.7.1.zip",
+    "panelUrl":  "https://bns-admin.sijbers.uk"
+}

pack/tweaks/README.md

@@ -0,0 +1,91 @@
+# Pack tweaks
+
+This folder is the source for any data-only NeoForge mods we ship with the
+modpack. Each subfolder becomes one jar at build time.
+
+The build pipeline:
+
+```
+pack/tweaks/<name>/  --(Build-Tweaks.ps1)-->  pack/overrides/mods/<name>-<ver>.jar
+                                                  |
+                                                  v
+                                         (Build-Pack.ps1 picks it up)
+                                                  |
+                                                  v
+                                         manifest.json -> launcher install
+```
+
+Because the output is a real mod jar (with `META-INF/neoforge.mods.toml`),
+the data inside auto-loads in **single-player and on the server** -- no
+`/datapack enable` needed, no per-world setup.
+
+---
+
+## Adding a new tweak (one big jar, recommended)
+
+The simplest workflow is to keep extending `brassandsigil-tweaks` with more
+worldgen / loot / recipe overrides. Just drop more JSON under
+`brassandsigil-tweaks/data/brassandsigil_tweaks/...`.
+
+Common targets:
+
+| What                              | Path                                                                    |
+| --------------------------------- | ----------------------------------------------------------------------- |
+| Custom configured feature (ore)   | `data/brassandsigil_tweaks/worldgen/configured_feature/<name>.json`     |
+| Custom placed feature             | `data/brassandsigil_tweaks/worldgen/placed_feature/<name>.json`         |
+| Lithostitched modifier            | `data/brassandsigil_tweaks/lithostitched/worldgen_modifier/<name>.json` |
+| Override another mod's loot table | `data/<their_modid>/loot_table/blocks/<name>.json`                      |
+| Override another mod's recipe     | `data/<their_modid>/recipe/<name>.json`                                 |
+| Override / extend a vanilla tag   | `data/minecraft/tags/<registry>/<name>.json`                            |
+
+After editing, bump the `version` in
+`brassandsigil-tweaks/META-INF/neoforge.mods.toml` so launcher clients see
+it as a new file and re-download.
+
+## Adding a separate tweak mod
+
+Make a sibling folder. The structure must be:
+
+```
+tweaks/
+  <my-tweak>/
+    META-INF/
+      neoforge.mods.toml      # modId + version are required
+    pack.mcmeta               # pack_format: 48 for 1.21.1
+    data/
+      <my_namespace>/
+        ...
+```
+
+`Build-Tweaks.ps1` reads `modId` and `version` from the toml and produces
+`pack/overrides/mods/<modId>-<version>.jar`. Old jars for the same `modId`
+are auto-cleaned, so version bumps don't leave stale files behind.
+
+---
+
+## What's in `brassandsigil-tweaks` today
+
+- **`skylands_end_stone_ore`** -- adds small End Stone veins to Terralith's
+  Skylands biomes (`#terralith:skylands`). Targets `stone_ore_replaceables`
+  so it only replaces the stone interior of the floating islands. Powers the
+  Aeronautics Levitite-blend recipe without forcing players to visit The
+  End. Tuning lives in
+  `data/brassandsigil_tweaks/worldgen/placed_feature/skylands_end_stone_ore.json`
+  (`count` = veins per chunk; `size` in the configured_feature controls vein size).
+
+---
+
+## Building
+
+From the repo root:
+
+```powershell
+# Builds tweak jars + manifest in one shot:
+.\scripts\Build-Pack.ps1 -OutputPath .\scripts\manifest.json
+
+# Just rebuild tweak jars:
+.\scripts\Build-Tweaks.ps1
+```
+
+Then deploy: `.\scripts\Deploy-Brass.ps1` mirrors `pack/overrides/` to the
+public share's `files/` subdir and pushes the regenerated manifest alongside.

pack/tweaks/brassandsigil-tweaks/META-INF/neoforge.mods.toml

@@ -0,0 +1,42 @@
+modLoader = "lowcodefml"
+loaderVersion = "[1,)"
+license = "All Rights Reserved"
+issueTrackerURL = "https://sijbers.uk/pack/"
+
+[[mods]]
+modId = "brassandsigil_tweaks"
+version = "1.0.0"
+displayName = "Brass & Sigil Tweaks"
+description = '''
+Server-and-client worldgen and balance tweaks for the Brass & Sigil modpack.
+Ships custom configured features, placed features, and Lithostitched worldgen
+modifiers that retune third-party content for this pack.
+'''
+
+[[dependencies.brassandsigil_tweaks]]
+    modId = "neoforge"
+    type = "required"
+    versionRange = "[21.1,)"
+    ordering = "NONE"
+    side = "BOTH"
+
+[[dependencies.brassandsigil_tweaks]]
+    modId = "minecraft"
+    type = "required"
+    versionRange = "[1.21.1,1.22)"
+    ordering = "NONE"
+    side = "BOTH"
+
+[[dependencies.brassandsigil_tweaks]]
+    modId = "lithostitched"
+    type = "required"
+    versionRange = "[1.7,)"
+    ordering = "NONE"
+    side = "BOTH"
+
+[[dependencies.brassandsigil_tweaks]]
+    modId = "terralith"
+    type = "required"
+    versionRange = "[2.5,)"
+    ordering = "AFTER"
+    side = "BOTH"

pack/tweaks/brassandsigil-tweaks/data/brassandsigil_tweaks/lithostitched/worldgen_modifier/skylands_end_stone.json

@@ -0,0 +1,6 @@
+{
+  "type": "lithostitched:add_features",
+  "biomes": "#terralith:skylands",
+  "features": "brassandsigil_tweaks:skylands_end_stone_ore",
+  "step": "underground_ores"
+}

pack/tweaks/brassandsigil-tweaks/data/brassandsigil_tweaks/worldgen/configured_feature/skylands_end_stone_ore.json

@@ -0,0 +1,18 @@
+{
+  "type": "minecraft:ore",
+  "config": {
+    "discard_chance_on_air_exposure": 0.0,
+    "size": 6,
+    "targets": [
+      {
+        "target": {
+          "predicate_type": "minecraft:tag_match",
+          "tag": "minecraft:stone_ore_replaceables"
+        },
+        "state": {
+          "Name": "minecraft:end_stone"
+        }
+      }
+    ]
+  }
+}

pack/tweaks/brassandsigil-tweaks/data/brassandsigil_tweaks/worldgen/placed_feature/skylands_end_stone_ore.json

@@ -0,0 +1,16 @@
+{
+  "feature": "brassandsigil_tweaks:skylands_end_stone_ore",
+  "placement": [
+    { "type": "minecraft:count", "count": 3 },
+    { "type": "minecraft:in_square" },
+    {
+      "type": "minecraft:height_range",
+      "height": {
+        "type": "minecraft:uniform",
+        "min_inclusive": { "absolute": 200 },
+        "max_inclusive": { "absolute": 250 }
+      }
+    },
+    { "type": "minecraft:biome" }
+  ]
+}

pack/tweaks/brassandsigil-tweaks/pack.mcmeta

@@ -0,0 +1,6 @@
+{
+  "pack": {
+    "pack_format": 48,
+    "description": "Brass & Sigil pack tweaks"
+  }
+}

scripts/Build-Pack.ps1

@@ -0,0 +1,183 @@
+#requires -Version 5
+<#
+.SYNOPSIS
+    Generates manifest.json deterministically from pack.lock.json.
+
+.DESCRIPTION
+    The lockfile (pack.lock.json) is the source of truth for every mod's exact
+    version, URL, SHA-1, and size. Running this script does not change versions.
+
+    To intentionally bump versions, use Update-Pack.ps1 with the -Refresh flag.
+    To see what new versions are available, use Check-Updates.ps1.
+
+    Workflow:
+      1. Edit pack.lock.json (manually or via Update-Pack.ps1 -Refresh)
+      2. Run Build-Pack.ps1 -OutputPath ...\manifest.json
+      3. Update the server to match
+      4. Deploy manifest to your hosted URL
+
+.PARAMETER OutputPath
+    Where to write manifest.json.
+
+.PARAMETER LocalPackSource
+    Optional folder containing local override files (configs, resourcepacks, etc.).
+
+.PARAMETER SelfHostBaseUrl
+    Public URL prefix for self-hosted files (only used when LocalPackSource is set).
+#>
+
+[CmdletBinding()]
+param(
+    [string]$OutputPath        = ".\manifest.json",
+    [string]$LocalPackSource   = "",
+    [string]$SelfHostBaseUrl   = "https://sijbers.uk/pack/files",
+    # Optional -- point at a published launcher .exe to embed launcherVersion + launcherUrl
+    # in the manifest. The launcher displays a "newer version available" banner when
+    # its embedded version is lower than this. Skip entirely to leave both fields out.
+    [string]$LauncherExePath   = "",
+    [string]$LauncherPublicUrl = "https://sijbers.uk/pack/BrassAndSigil-Launcher.exe",
+    # Skip the auto-invoke of Build-Tweaks.ps1 (only touch this if you're debugging).
+    [switch]$SkipTweaks
+)
+
+$ErrorActionPreference = 'Stop'
+$ProgressPreference    = 'SilentlyContinue'
+
+$here     = Split-Path -Parent $MyInvocation.MyCommand.Path
+$lockPath = Join-Path $here '..\pack\pack.lock.json'
+
+# Build any data-only tweak jars first, then fold the resulting overrides
+# folder into the manifest. Set -SkipTweaks to bypass. The "overrides" name
+# matches CurseForge/Modrinth modpack conventions: files that override or
+# augment the standard mod set, hosted by us.
+$tweaksRoot    = Join-Path $here '..\pack\tweaks'
+$overridesRoot = Join-Path $here '..\pack\overrides'
+if (-not $SkipTweaks -and (Test-Path $tweaksRoot)) {
+    & (Join-Path $here 'Build-Tweaks.ps1') -TweaksRoot $tweaksRoot -OutputRoot (Join-Path $overridesRoot 'mods')
+}
+if (-not $LocalPackSource -and (Test-Path $overridesRoot)) {
+    $LocalPackSource = $overridesRoot
+}
+
+if (-not (Test-Path $lockPath)) {
+    throw "pack.lock.json not found at $lockPath. Run Update-Pack.ps1 -Refresh first to bootstrap it."
+}
+
+$lock = Get-Content $lockPath -Raw | ConvertFrom-Json
+
+Write-Host ""
+Write-Host "Building manifest from pack.lock.json:"
+Write-Host ("  Pack:     {0} v{1}" -f $lock.name, $lock.version)
+Write-Host ("  MC:       {0} ({1} {2})" -f $lock.minecraft, $lock.loader.type, $lock.loader.version)
+Write-Host ("  Locked:   {0}" -f $lock.lockedAt)
+Write-Host ("  Mods:     {0}" -f $lock.mods.Count)
+Write-Host ""
+
+$files = @()
+$totalBytes = 0L
+
+foreach ($mod in $lock.mods) {
+    $files += [pscustomobject]@{
+        path = $mod.path
+        url  = $mod.url
+        sha1 = $mod.sha1
+        size = $mod.size
+    }
+    $totalBytes += $mod.size
+    Write-Host ("  [{0}] {1,-26} {2,-22} {3,8:N0} KB" -f $mod.source.PadRight(7).Substring(0,7), $mod.slug, $mod.version, ($mod.size/1KB))
+}
+
+# Local overrides (configs, custom files not on Modrinth/CurseForge)
+if ($LocalPackSource -and (Test-Path $LocalPackSource)) {
+    Write-Host ""
+    Write-Host "Adding local overrides from $LocalPackSource..."
+    $managedRoots = @('mods', 'config', 'resourcepacks', 'shaderpacks', 'kubejs', 'defaultconfigs')
+    $base = $SelfHostBaseUrl.TrimEnd('/')
+    $sourceFull = (Resolve-Path $LocalPackSource).Path.TrimEnd('\','/')
+    foreach ($root in $managedRoots) {
+        $rootDir = Join-Path $LocalPackSource $root
+        if (-not (Test-Path $rootDir)) { continue }
+        Get-ChildItem -Path $rootDir -Recurse -File | ForEach-Object {
+            $rel = $_.FullName.Substring($sourceFull.Length).TrimStart('\','/') -replace '\\','/'
+            $sha1 = (Get-FileHash -Algorithm SHA1 -Path $_.FullName).Hash.ToLowerInvariant()
+            $files += [pscustomobject]@{
+                path = $rel
+                url  = "$base/$rel"
+                sha1 = $sha1
+                size = $_.Length
+            }
+            $totalBytes += $_.Length
+            Write-Host ("  [local]   {0}" -f $rel)
+        }
+    }
+}
+
+$manifest = [ordered]@{
+    name      = $lock.name
+    version   = $lock.version
+    minecraft = [ordered]@{ version = $lock.minecraft }
+    loader    = [ordered]@{ type = $lock.loader.type; version = $lock.loader.version }
+    files     = $files
+}
+
+# Optional: copy a defaultServer block through from the lockfile so the launcher
+# can pre-populate friends' multiplayer list. Lockfile schema:
+#   "defaultServer": { "name": "Brass & Sigil", "ip": "bns.sijbers.uk" }
+if ($lock.PSObject.Properties.Name -contains "defaultServer" -and $lock.defaultServer) {
+    $manifest.defaultServer = [ordered]@{
+        name = $lock.defaultServer.name
+        ip   = $lock.defaultServer.ip
+    }
+    Write-Host ("  Default server: {0} ({1})" -f $lock.defaultServer.name, $lock.defaultServer.ip)
+}
+
+# Optional: shader pack to enable by default on fresh installs. Lockfile schema:
+#   "defaultShader": "ComplementaryReimagined_r5.7.1.zip"
+if ($lock.PSObject.Properties.Name -contains "defaultShader" -and $lock.defaultShader) {
+    $manifest.defaultShader = $lock.defaultShader
+    Write-Host ("  Default shader: {0}" -f $lock.defaultShader)
+}
+
+# Optional: public URL of the brass-sigil-server panel. Used by the launcher
+# to send friend-side whitelist requests. Lockfile schema:
+#   "panelUrl": "https://bns-admin.sijbers.uk"
+if ($lock.PSObject.Properties.Name -contains "panelUrl" -and $lock.panelUrl) {
+    $manifest.panelUrl = $lock.panelUrl
+    Write-Host ("  Panel URL: {0}" -f $lock.panelUrl)
+}
+
+# Optional launcher metadata: when -LauncherExePath is supplied, read the exe's
+# FileVersion (set via <Version> in ModpackLauncher.csproj) and embed it. The
+# launcher compares its assembly version to this value and shows an upgrade
+# banner pointing at LauncherPublicUrl when older.
+if ($LauncherExePath) {
+    if (-not (Test-Path $LauncherExePath)) {
+        throw "LauncherExePath '$LauncherExePath' does not exist."
+    }
+    $launcherFile = Get-Item $LauncherExePath
+    $launcherVersion = $launcherFile.VersionInfo.FileVersion
+    if ([string]::IsNullOrWhiteSpace($launcherVersion)) {
+        throw "Launcher exe has no FileVersion -- set <Version> in ModpackLauncher.csproj and republish."
+    }
+    # FileVersion is the four-component form (e.g. "0.1.0.0" for csproj <Version>0.1.0</Version>).
+    # Embed as-is -- the launcher's Version.Parse handles it directly and avoids ambiguous
+    # comparisons between trimmed and untrimmed forms.
+    $manifest.launcherVersion = $launcherVersion
+    $manifest.launcherUrl     = $LauncherPublicUrl
+
+    Write-Host ""
+    Write-Host ("Launcher metadata embedded:")
+    Write-Host ("  Version:  {0}" -f $launcherVersion)
+    Write-Host ("  Url:      {0}" -f $LauncherPublicUrl)
+    Write-Host ("  Source:   {0}" -f $launcherFile.FullName)
+}
+
+$json = $manifest | ConvertTo-Json -Depth 10
+$outDir = Split-Path -Parent $OutputPath
+if ($outDir -and -not (Test-Path $outDir)) { New-Item -ItemType Directory -Path $outDir | Out-Null }
+[System.IO.File]::WriteAllText($OutputPath, $json, [System.Text.UTF8Encoding]::new($false))
+
+Write-Host ""
+Write-Host "Manifest written: $OutputPath"
+Write-Host ("  Files:    {0}" -f $files.Count)
+Write-Host ("  Total:    {0:N1} MB (download size)" -f ($totalBytes / 1MB))

scripts/Build-Tweaks.ps1

@@ -0,0 +1,115 @@
+#requires -Version 5
+<#
+.SYNOPSIS
+    Builds every tweak source folder under ..\pack\tweaks\ into a data-only
+    mod jar and drops it into ..\pack\overrides\mods\.
+
+.DESCRIPTION
+    Each subfolder of ..\pack\tweaks\ is treated as one self-contained
+    "data-only" NeoForge mod. Its modId, version, and display name come from
+    the folder's META-INF\neoforge.mods.toml. The script:
+
+      1. Reads modId + version from neoforge.mods.toml.
+      2. Zips the folder contents (data\, META-INF\, pack.mcmeta) into a jar
+         named "<modId>-<version>.jar".
+      3. Removes any older jars for the same modId from the output folder so
+         stale versions don't get bundled into the manifest.
+
+    Run this before Build-Pack.ps1, or let Build-Pack.ps1 invoke it for you.
+
+.PARAMETER TweaksRoot
+    Folder containing tweak source subfolders. Defaults to ..\pack\tweaks\.
+
+.PARAMETER OutputRoot
+    Where built jars go. Defaults to ..\pack\overrides\mods\. This path
+    becomes Build-Pack.ps1's -LocalPackSource (one level up).
+#>
+
+[CmdletBinding()]
+param(
+    [string]$TweaksRoot = "",
+    [string]$OutputRoot = ""
+)
+
+$ErrorActionPreference = 'Stop'
+$ProgressPreference    = 'SilentlyContinue'
+
+$here = Split-Path -Parent $MyInvocation.MyCommand.Path
+if (-not $TweaksRoot) { $TweaksRoot = Join-Path $here '..\pack\tweaks' }
+if (-not $OutputRoot) { $OutputRoot = Join-Path $here '..\pack\overrides\mods' }
+
+if (-not (Test-Path $TweaksRoot)) {
+    Write-Host "No tweaks folder at $TweaksRoot -- nothing to build."
+    return
+}
+
+if (-not (Test-Path $OutputRoot)) {
+    New-Item -ItemType Directory -Path $OutputRoot -Force | Out-Null
+}
+
+# Read modId + version out of a neoforge.mods.toml. We do this with a tiny regex
+# parser instead of a full TOML library because we only need two scalars and we
+# control the file format. Lines like:  modId = "foo"   version = "1.2.3"
+function Get-ModMeta {
+    param([string]$TomlPath)
+    if (-not (Test-Path $TomlPath)) {
+        throw "Missing $TomlPath -- every tweak folder needs META-INF\neoforge.mods.toml."
+    }
+    $content = Get-Content $TomlPath -Raw
+
+    $modIdMatch = [regex]::Match($content, '(?m)^\s*modId\s*=\s*"([^"]+)"')
+    $versionMatch = [regex]::Match($content, '(?m)^\s*version\s*=\s*"([^"]+)"')
+
+    if (-not $modIdMatch.Success)   { throw "Could not parse modId from $TomlPath" }
+    if (-not $versionMatch.Success) { throw "Could not parse version from $TomlPath" }
+
+    return [pscustomobject]@{
+        ModId   = $modIdMatch.Groups[1].Value
+        Version = $versionMatch.Groups[1].Value
+    }
+}
+
+Add-Type -AssemblyName System.IO.Compression.FileSystem
+
+$tweakDirs = Get-ChildItem -Path $TweaksRoot -Directory
+
+if ($tweakDirs.Count -eq 0) {
+    Write-Host "No tweak folders found under $TweaksRoot."
+    return
+}
+
+Write-Host ""
+Write-Host "Building tweak jars from $TweaksRoot"
+Write-Host ""
+
+foreach ($dir in $tweakDirs) {
+    $tomlPath = Join-Path $dir.FullName 'META-INF\neoforge.mods.toml'
+    $meta = Get-ModMeta -TomlPath $tomlPath
+
+    $jarName = "$($meta.ModId)-$($meta.Version).jar"
+    $jarPath = Join-Path $OutputRoot $jarName
+
+    # Wipe stale jars for this modId so old versions don't get bundled into
+    # the manifest alongside the new one.
+    Get-ChildItem -Path $OutputRoot -Filter "$($meta.ModId)-*.jar" -ErrorAction SilentlyContinue |
+        Where-Object { $_.Name -ne $jarName } |
+        ForEach-Object {
+            Write-Host ("  removing stale: {0}" -f $_.Name)
+            Remove-Item $_.FullName -Force
+        }
+
+    if (Test-Path $jarPath) { Remove-Item $jarPath -Force }
+
+    [System.IO.Compression.ZipFile]::CreateFromDirectory(
+        $dir.FullName,
+        $jarPath,
+        [System.IO.Compression.CompressionLevel]::Optimal,
+        $false
+    )
+
+    $size = (Get-Item $jarPath).Length
+    Write-Host ("  built {0,-40} {1,8:N0} bytes" -f $jarName, $size)
+}
+
+Write-Host ""
+Write-Host "Tweak jars are in: $OutputRoot"

scripts/Check-Updates.ps1

@@ -0,0 +1,101 @@
+#requires -Version 5
+<#
+.SYNOPSIS
+    Read-only update checker. Diffs the locked Modrinth versions against the
+    latest available on Modrinth. Prints a report. Does not change anything.
+
+.DESCRIPTION
+    Run this periodically to see what mod updates are available without
+    committing to anything. Decide which to bump, then either edit pack.lock.json
+    by hand or re-run Update-Pack.ps1 to refresh everything.
+
+    CurseForge mods (FTB family) aren't auto-checked here -- CF requires an API
+    key for proper version listing. Manually monitor those at:
+      https://www.curseforge.com/minecraft/mc-mods/ftb-chunks-forge
+      https://www.curseforge.com/minecraft/mc-mods/ftb-library-forge
+      https://www.curseforge.com/minecraft/mc-mods/ftb-teams-forge
+#>
+
+[CmdletBinding()]
+param()
+
+$ErrorActionPreference = 'Stop'
+$ProgressPreference    = 'SilentlyContinue'
+
+$here     = Split-Path -Parent $MyInvocation.MyCommand.Path
+$lockPath = Join-Path $here '..\pack\pack.lock.json'
+
+if (-not (Test-Path $lockPath)) {
+    throw "pack.lock.json not found. Run Update-Pack.ps1 first to bootstrap it."
+}
+
+$lock = Get-Content $lockPath -Raw | ConvertFrom-Json
+$mc   = $lock.minecraft
+$lt   = $lock.loader.type
+
+Write-Host ""
+Write-Host "Checking Modrinth for newer versions..."
+Write-Host ("  Pack:   $($lock.name) v$($lock.version)")
+Write-Host ("  MC:     $mc ($lt $($lock.loader.version))")
+Write-Host ("  Locked: $($lock.lockedAt)")
+Write-Host ""
+
+Add-Type -AssemblyName System.Web
+
+function Invoke-Modrinth {
+    param([string]$Path)
+    Invoke-RestMethod -Uri "https://api.modrinth.com/v2$Path" -Headers @{ 'User-Agent' = 'BrassAndSigil-Launcher/0.1 (matt@sijbers.uk)' }
+}
+
+$updatesAvailable = 0
+$upToDate = 0
+$skipped = 0
+
+foreach ($mod in $lock.mods) {
+    if ($mod.source -ne "modrinth") {
+        Write-Host ("  [cforge]  $($mod.slug.PadRight(22)) $($mod.version.PadRight(34)) (manual check)")
+        $skipped++
+        continue
+    }
+
+    try {
+        $encGv = [System.Web.HttpUtility]::UrlEncode('["' + $mc + '"]')
+        $encL  = [System.Web.HttpUtility]::UrlEncode('["' + $lt + '"]')
+        $versions = Invoke-Modrinth ("/project/$($mod.slug)/version?game_versions=$encGv" + "&" + "loaders=$encL")
+    } catch {
+        Write-Warning "  [error]   $($mod.slug) - $($_.Exception.Message)"
+        continue
+    }
+    if (-not $versions -or $versions.Count -eq 0) {
+        Write-Warning "  [gone]    $($mod.slug) - no versions found on Modrinth"
+        continue
+    }
+
+    $latest = $versions[0]
+    $latestVer = $latest.version_number
+    $latestType = $latest.version_type
+
+    if ($latest.id -eq $mod.versionId) {
+        Write-Host ("  [ok]      $($mod.slug.PadRight(22)) $($mod.version.PadRight(34)) (current)")
+        $upToDate++
+    }
+    else {
+        $tag = if ($latestType -eq 'beta') { '[update*]' } else { '[update] ' }
+        Write-Host ("  $tag $($mod.slug.PadRight(22)) $($mod.version.PadRight(34)) -> $latestVer") -ForegroundColor Yellow
+        $updatesAvailable++
+    }
+}
+
+Write-Host ""
+Write-Host "Summary:"
+Write-Host ("  Up to date:   $upToDate")
+$updateColor = if ($updatesAvailable -gt 0) { 'Yellow' } else { 'White' }
+Write-Host ("  Updates:      $updatesAvailable") -ForegroundColor $updateColor
+Write-Host ("  Manual check: $skipped (CurseForge)")
+Write-Host ""
+if ($updatesAvailable -gt 0) {
+    Write-Host "[update*] = beta release. Bump only if you specifically want it."
+    Write-Host ""
+    Write-Host "To take all updates: run Update-Pack.ps1 (then Build-Pack.ps1 + deploy server)."
+    Write-Host "To pick selectively: edit pack.lock.json by hand, then run Build-Pack.ps1."
+}

scripts/Deploy-Brass.ps1

@@ -0,0 +1,231 @@
+#requires -Version 5
+<#
+.SYNOPSIS
+    One-shot deploy: build launcher + server, regenerate manifest, mirror the
+    deploy share, scp the server binary.
+
+.DESCRIPTION
+    Reads `deploy.config.ps1` (sibling file, gitignored) for local paths +
+    SSH details. Stages run in order; -Stage limits which stages run.
+
+    The script does NOT auto-restart the production daemon. After a server
+    binary deploy it prompts you to do that yourself.
+
+.PARAMETER Stage
+    All | Launcher | Server | Pack. Defaults to All.
+
+      Launcher = build launcher + regenerate manifest + push to deploy share
+      Server   = build server + scp binary (atomic swap)
+      Pack     = regenerate manifest + mirror pack/overrides/* to share
+      All      = everything, in order
+
+.PARAMETER SkipBuild
+    Skip dotnet publish steps. Use when you've already built and just want
+    to push artifacts.
+
+.PARAMETER DryRun
+    Print each action without executing. No files copied, no SSH, no build.
+#>
+
+[CmdletBinding()]
+param(
+    [ValidateSet('All','Launcher','Server','Pack')]
+    [string]$Stage = 'All',
+    [switch]$SkipBuild,
+    [switch]$DryRun,
+    # Skip the version-bump check. Use only for cosmetic/internal-only changes
+    # where you're SURE clients don't need to re-sync. The default is to refuse
+    # if the local pack/launcher version matches what's already deployed.
+    [switch]$Force
+)
+
+$ErrorActionPreference = 'Stop'
+$ProgressPreference    = 'SilentlyContinue'
+
+# ─── Resolve repo + load config ────────────────────────────────────────────
+$here     = Split-Path -Parent $MyInvocation.MyCommand.Path
+$repoRoot = Resolve-Path (Join-Path $here '..')
+$cfgPath  = Join-Path $here 'deploy.config.ps1'
+if (-not (Test-Path $cfgPath)) {
+    throw "Missing $cfgPath. Copy deploy.config.template.ps1 -> deploy.config.ps1 and fill in real values."
+}
+. $cfgPath
+
+# Sanity-check required vars actually got set (template ships with CHANGE_ME).
+foreach ($v in 'DeployShare','ServerSshHost','ServerSshKey','ServerBinaryRemote') {
+    $val = Get-Variable -Name $v -ValueOnly -ErrorAction Stop
+    if ($val -match 'CHANGE_ME' -or [string]::IsNullOrWhiteSpace($val)) {
+        throw "deploy.config.ps1 has placeholder/empty `$$v. Fill it in."
+    }
+}
+
+$shouldRunLauncher = $Stage -in @('All','Launcher')
+$shouldRunServer   = $Stage -in @('All','Server')
+$shouldRunPack     = $Stage -in @('All','Launcher','Pack')   # manifest needs launcher exe meta
+
+# ─── Pre-flight: version-bump check ────────────────────────────────────────
+# The launcher caches the pack by version: a client that already synced
+# pack v0.9.2 will short-circuit at "already on 0.9.2" if you re-deploy
+# under the same version, even if the file list / SHAs changed. Same idea
+# applies to launcherVersion (drives the in-launcher upgrade banner).
+# We fetch the currently-deployed manifest and refuse to deploy if the
+# matching version field hasn't been bumped. Use -Force to override (e.g.
+# for cosmetic-only changes where re-sync isn't needed).
+if (($shouldRunPack -or $shouldRunLauncher) -and -not $DryRun -and -not $Force) {
+    if (-not $ManifestPublicUrl -or $ManifestPublicUrl -match 'CHANGE_ME') {
+        throw "deploy.config.ps1 is missing `$ManifestPublicUrl. Set it to the deployed manifest URL (e.g. https://example.com/pack/manifest.json)."
+    }
+    $deployed = $null
+    try {
+        $deployed = Invoke-RestMethod -Uri $ManifestPublicUrl -TimeoutSec 8
+    } catch {
+        Write-Host "Pre-flight: couldn't fetch deployed manifest at $ManifestPublicUrl -- version check skipped (probably first deploy)." -ForegroundColor DarkGray
+    }
+    if ($deployed) {
+        $errs = @()
+        # Pack version check applies only when the user is explicitly deploying
+        # pack content (Stage = All or Pack). A launcher-only deploy intentionally
+        # leaves pack content alone, so the pack version SHOULD stay constant.
+        $strictPackCheck = $Stage -in @('All','Pack')
+        if ($strictPackCheck) {
+            $lock = Get-Content (Join-Path $repoRoot 'pack\pack.lock.json') -Raw | ConvertFrom-Json
+            if ($deployed.version -eq $lock.version) {
+                $errs += "Pack version is unchanged ($($lock.version)). Clients cached at that version will SKIP the sync -- they won't pick up your pack changes. Bump 'version' in pack/pack.lock.json before deploying."
+            }
+        }
+        if ($shouldRunLauncher) {
+            $csprojPath = Join-Path $repoRoot 'launcher\ModpackLauncher.csproj'
+            [xml]$csproj = Get-Content $csprojPath
+            $localLauncherVersion = ($csproj.Project.PropertyGroup.Version | Where-Object { $_ }) | Select-Object -First 1
+            # Manifest stores 4-part FileVersion (e.g. "0.4.4.0"); csproj <Version> is 3-part ("0.4.4"). Compare normalised.
+            $deployedNorm = ($deployed.launcherVersion -replace '\.0+$','')
+            $localNorm    = ($localLauncherVersion -replace '\.0+$','')
+            if ($deployedNorm -eq $localNorm -and $localNorm) {
+                $errs += "Launcher version is unchanged ($localLauncherVersion). Existing 0.4.x installs won't see an upgrade prompt -- bump <Version> in launcher/ModpackLauncher.csproj before deploying."
+            }
+        }
+        if ($errs.Count -gt 0) {
+            Write-Host ""
+            Write-Host "VERSION-BUMP CHECK FAILED:" -ForegroundColor Red
+            foreach ($e in $errs) { Write-Host "  - $e" -ForegroundColor Red }
+            Write-Host ""
+            Write-Host "If you're re-deploying without any user-visible changes, pass -Force to skip this check." -ForegroundColor DarkGray
+            exit 1
+        }
+    }
+}
+
+# ─── Pre-flight: was the daemon already running? ───────────────────────────
+# We don't auto-stop it (kicks active players to fix a problem that isn't
+# actually broken -- the atomic swap is safe with the daemon running). But
+# knowing the state up front lets us tailor the final "next steps" message
+# so a deploy success doesn't silently leave you on the old code.
+$daemonWasRunning = $false
+if ($shouldRunServer) {
+    Write-Host "Pre-flight: checking daemon state on $ServerSshHost..." -ForegroundColor DarkGray
+    # Single-quoted PS string so PowerShell doesn't try to interpret the
+    # bash-side metacharacters. The remote shell sees the literal pgrep
+    # command; the trailing $ anchors so we don't match run.sh wrappers.
+    $remoteCmd = 'pgrep -f /brass-sigil-server$ 2>/dev/null'
+    $pgrepOut = & ssh -i $ServerSshKey -o ConnectTimeout=5 -o BatchMode=yes $ServerSshHost $remoteCmd 2>$null
+    $daemonWasRunning = -not [string]::IsNullOrWhiteSpace($pgrepOut)
+    if ($daemonWasRunning) {
+        Write-Host "  Daemon is RUNNING. Atomic swap is safe -- but you'll need to" -ForegroundColor Yellow
+        Write-Host "  stop+start it after deploy for the new code to take effect." -ForegroundColor Yellow
+    } else {
+        Write-Host "  Daemon is stopped. New binary will run as soon as you start it." -ForegroundColor DarkGray
+    }
+}
+
+# ─── Helpers ───────────────────────────────────────────────────────────────
+$stepNum = 0
+function Step($desc, [scriptblock]$body) {
+    $script:stepNum++
+    $start = Get-Date
+    Write-Host ""
+    Write-Host ("[{0}] {1}" -f $script:stepNum, $desc) -ForegroundColor Cyan
+    if ($DryRun) {
+        Write-Host "      (dry-run, skipping)" -ForegroundColor DarkGray
+        return
+    }
+    & $body
+    $elapsed = (Get-Date) - $start
+    Write-Host ("      done in {0:N1}s" -f $elapsed.TotalSeconds) -ForegroundColor DarkGray
+}
+
+# ─── Stage 1: build launcher ───────────────────────────────────────────────
+$launcherExe = Join-Path $repoRoot (Join-Path $LauncherPublishDir $LauncherExeName)
+if ($shouldRunLauncher -and -not $SkipBuild) {
+    Step "Build launcher (dotnet publish launcher\)" {
+        Push-Location (Join-Path $repoRoot 'launcher')
+        try   { dotnet publish -c Release -nologo | Out-Host }
+        finally { Pop-Location }
+        if (-not (Test-Path $launcherExe)) { throw "Launcher publish didn't produce $launcherExe" }
+    }
+}
+
+# ─── Stage 2: build server ─────────────────────────────────────────────────
+$serverExe = Join-Path $repoRoot (Join-Path $ServerPublishDir $ServerExeName)
+if ($shouldRunServer -and -not $SkipBuild) {
+    Step "Build server (dotnet publish server\ -r linux-x64)" {
+        Push-Location (Join-Path $repoRoot 'server')
+        try   { dotnet publish -c Release -r linux-x64 --self-contained true -nologo | Out-Host }
+        finally { Pop-Location }
+        if (-not (Test-Path $serverExe)) { throw "Server publish didn't produce $serverExe" }
+    }
+}
+
+# ─── Stage 3: regenerate manifest ──────────────────────────────────────────
+$manifestPath = Join-Path $here 'manifest.json'
+if ($shouldRunPack) {
+    Step "Regenerate manifest (Build-Pack.ps1)" {
+        $args = @{ OutputPath = $manifestPath }
+        if ($shouldRunLauncher -and (Test-Path $launcherExe)) { $args.LauncherExePath = $launcherExe }
+        & (Join-Path $here 'Build-Pack.ps1') @args | Out-Host
+    }
+}
+
+# ─── Stage 4: mirror pack overrides to share ──────────────────────────────
+$overridesLocal = Join-Path $repoRoot 'pack\overrides'
+$shareFiles     = Join-Path $DeployShare 'files'
+if ($shouldRunPack -and (Test-Path $overridesLocal)) {
+    Step "Mirror pack/overrides/ -> $shareFiles" {
+        # /MIR makes destination match source (deletes orphan files in $shareFiles).
+        # /XJ skips junctions, /R:1 /W:1 keeps retry behaviour sane on flaky shares.
+        robocopy $overridesLocal $shareFiles /MIR /XJ /R:1 /W:1 /NFL /NDL /NJH /NJS /NP | Out-Host
+        # Robocopy returns 0-7 for success-with-info; 8+ is real failure.
+        if ($LASTEXITCODE -ge 8) { throw "robocopy failed with exit $LASTEXITCODE" }
+    }
+}
+
+# ─── Stage 5: deploy launcher exe + manifest to share ──────────────────────
+if ($shouldRunLauncher) {
+    Step "Copy launcher.exe + manifest to $DeployShare" {
+        Copy-Item $launcherExe (Join-Path $DeployShare $LauncherDeployedAs) -Force
+        Copy-Item $manifestPath (Join-Path $DeployShare 'manifest.json')   -Force
+    }
+}
+
+# ─── Stage 6: scp + atomic swap server binary ──────────────────────────────
+if ($shouldRunServer) {
+    Step "scp server binary -> $ServerSshHost`:$ServerBinaryRemote (atomic swap)" {
+        $remoteNew = "$ServerBinaryRemote.new"
+        & scp -i $ServerSshKey -o ConnectTimeout=15 $serverExe "$ServerSshHost`:$remoteNew"
+        if ($LASTEXITCODE -ne 0) { throw "scp failed with exit $LASTEXITCODE" }
+        $cmd = "chmod +x '$remoteNew' && mv '$remoteNew' '$ServerBinaryRemote' && md5sum '$ServerBinaryRemote'"
+        & ssh -i $ServerSshKey -o ConnectTimeout=10 $ServerSshHost $cmd
+        if ($LASTEXITCODE -ne 0) { throw "ssh swap failed with exit $LASTEXITCODE" }
+    }
+    Write-Host ""
+    if ($daemonWasRunning) {
+        Write-Host "Server binary swapped on disk, but the daemon was running before this" -ForegroundColor Yellow
+        Write-Host "deploy and is still on the OLD code in memory (Linux preserves the running" -ForegroundColor Yellow
+        Write-Host "inode through rename). Stop + start the daemon to pick up the new build." -ForegroundColor Yellow
+    } else {
+        Write-Host "Server binary swapped on disk. Daemon was stopped -- start it whenever" -ForegroundColor Green
+        Write-Host "you're ready and it'll run the new build." -ForegroundColor Green
+    }
+}
+
+Write-Host ""
+Write-Host "Deploy finished." -ForegroundColor Green

scripts/Update-Pack.ps1

@@ -0,0 +1,207 @@
+#requires -Version 5
+<#
+.SYNOPSIS
+    Refreshes pack.lock.json by querying Modrinth + CurseForge for the latest
+    compatible version of each mod listed below.
+
+.DESCRIPTION
+    THIS SCRIPT MUTATES pack.lock.json. Run only when you intentionally want to
+    bump versions (and remember to update the server to match).
+
+    For non-mutating "what's available?" reports, run Check-Updates.ps1.
+
+.PARAMETER PackName
+.PARAMETER PackVersion
+.PARAMETER MinecraftVersion
+.PARAMETER LoaderType
+.PARAMETER LoaderVersion
+    Override pack metadata. Defaults read from existing lockfile if present.
+#>
+
+[CmdletBinding()]
+param(
+    [string]$PackName          = "",
+    [string]$PackVersion       = "",
+    [string]$MinecraftVersion  = "1.21.1",
+    [string]$LoaderType        = "neoforge",
+    [string]$LoaderVersion     = ""
+)
+
+$ErrorActionPreference = 'Stop'
+$ProgressPreference    = 'SilentlyContinue'
+
+$here     = Split-Path -Parent $MyInvocation.MyCommand.Path
+$lockPath = Join-Path $here '..\pack\pack.lock.json'
+
+# Read existing lock for defaults
+$existing = if (Test-Path $lockPath) { Get-Content $lockPath -Raw | ConvertFrom-Json } else { $null }
+if (-not $PackName     -and $existing) { $PackName     = $existing.name }
+if (-not $PackVersion  -and $existing) { $PackVersion  = $existing.version }
+if (-not $LoaderVersion -and $existing) { $LoaderVersion = $existing.loader.version }
+if (-not $PackName)     { $PackName     = "Brass and Sigil" }
+if (-not $PackVersion)  { $PackVersion  = "0.6.0" }
+if (-not $LoaderVersion) { $LoaderVersion = "21.1.228" }
+
+# ---------------------------------------------------------------------------
+# Mod definitions: edit here when adding/removing mods. allowBeta=true allows
+# fallback to beta if no release exists.
+# ---------------------------------------------------------------------------
+$modrinthMods = @(
+    @{ slug = "create";              allowBeta = $false }
+    @{ slug = "create-aeronautics";  allowBeta = $false }
+    @{ slug = "sable";               allowBeta = $false }
+    @{ slug = "create-big-cannons";  allowBeta = $false }
+    @{ slug = "create-tfmg";         allowBeta = $false }
+    @{ slug = "distanthorizons";     allowBeta = $true  }
+    @{ slug = "sodium";              allowBeta = $false }
+    @{ slug = "iris";                allowBeta = $false }
+    @{ slug = "modernfix";           allowBeta = $false }
+    @{ slug = "ferrite-core";        allowBeta = $false }
+    @{ slug = "architectury-api";    allowBeta = $false }
+    @{ slug = "rhino";               allowBeta = $true  }
+    @{ slug = "rpl";                 allowBeta = $false }
+    @{ slug = "kubejs";              allowBeta = $false }
+    @{ slug = "jei";                 allowBeta = $true  }
+    @{ slug = "jade";                allowBeta = $false }
+    @{ slug = "chunky";              allowBeta = $false }
+)
+
+# CurseForge mods aren't auto-resolved (no public API without a key).
+# Update fileId/version/filename here when bumping.
+$curseforgeMods = @(
+    @{
+        slug     = "ftb-library"
+        version  = "2101.1.31"
+        fileId   = "7746959"
+        path     = "mods/ftb-library-neoforge-2101.1.31.jar"
+        url      = "https://mediafilez.forgecdn.net/files/7746/959/ftb-library-neoforge-2101.1.31.jar"
+    }
+    @{
+        slug     = "ftb-teams"
+        version  = "2101.1.9"
+        fileId   = "7369021"
+        path     = "mods/ftb-teams-neoforge-2101.1.9.jar"
+        url      = "https://mediafilez.forgecdn.net/files/7369/21/ftb-teams-neoforge-2101.1.9.jar"
+    }
+    @{
+        slug     = "ftb-chunks"
+        version  = "2101.1.14"
+        fileId   = "7608681"
+        path     = "mods/ftb-chunks-neoforge-2101.1.14.jar"
+        url      = "https://mediafilez.forgecdn.net/files/7608/681/ftb-chunks-neoforge-2101.1.14.jar"
+    }
+)
+
+Add-Type -AssemblyName System.Web
+
+function Invoke-Modrinth {
+    param([string]$Path)
+    Invoke-RestMethod -Uri "https://api.modrinth.com/v2$Path" -Headers @{ 'User-Agent' = 'BrassAndSigil-Launcher/0.1 (matt@sijbers.uk)' }
+}
+
+function Get-LatestModrinthVersion {
+    param([string]$Slug, [bool]$AllowBeta)
+    $encGv = [System.Web.HttpUtility]::UrlEncode('["' + $MinecraftVersion + '"]')
+    $encL  = [System.Web.HttpUtility]::UrlEncode('["' + $LoaderType + '"]')
+    $versions = Invoke-Modrinth ("/project/$Slug/version?game_versions=$encGv" + "&" + "loaders=$encL")
+    if (-not $versions -or $versions.Count -eq 0) { return $null }
+    if ($AllowBeta) {
+        # Take the newest version regardless of stability (Modrinth orders newest first).
+        return $versions[0]
+    }
+    # Stable-only: latest release version, or null if there's no release at all.
+    return $versions | Where-Object { $_.version_type -eq 'release' } | Select-Object -First 1
+}
+
+$lockedMods = @()
+$missing = @()
+
+Write-Host ""
+Write-Host "Querying Modrinth for $($modrinthMods.Count) mods (MC $MinecraftVersion / $LoaderType)..."
+Write-Host ""
+
+foreach ($mod in $modrinthMods) {
+    try {
+        $version = Get-LatestModrinthVersion -Slug $mod.slug -AllowBeta $mod.allowBeta
+    } catch {
+        Write-Warning "  [error]   $($mod.slug) - $($_.Exception.Message)"
+        $missing += $mod.slug
+        continue
+    }
+    if (-not $version) {
+        Write-Warning "  [missing] $($mod.slug) - no compatible version"
+        $missing += $mod.slug
+        continue
+    }
+    $primary = $version.files | Where-Object { $_.primary -eq $true } | Select-Object -First 1
+    if (-not $primary) { $primary = $version.files[0] }
+
+    $lockedMods += [ordered]@{
+        source    = "modrinth"
+        slug      = $mod.slug
+        versionId = $version.id
+        version   = $version.version_number
+        path      = "mods/$($primary.filename)"
+        url       = $primary.url
+        sha1      = $primary.hashes.sha1
+        size      = $primary.size
+    }
+
+    $tag = if ($version.version_type -eq 'beta') { '[beta]   ' } else { '[release]' }
+    Write-Host ("  $tag $($mod.slug.PadRight(22)) $($version.version_number.PadRight(28))")
+}
+
+Write-Host ""
+Write-Host "Hashing $($curseforgeMods.Count) CurseForge mods (manual entries)..."
+$tmpDir = Join-Path $env:TEMP "brassandsigil-cf-cache"
+if (-not (Test-Path $tmpDir)) { New-Item -ItemType Directory -Path $tmpDir | Out-Null }
+
+foreach ($cf in $curseforgeMods) {
+    $fname = Split-Path -Leaf $cf.path
+    $tmpFile = Join-Path $tmpDir $fname
+    try {
+        if (-not (Test-Path $tmpFile)) {
+            Invoke-WebRequest -Uri $cf.url -OutFile $tmpFile -UseBasicParsing -Headers @{ 'User-Agent' = 'BrassAndSigil-Launcher/0.1 (matt@sijbers.uk)' }
+        }
+        $sha1 = (Get-FileHash -Algorithm SHA1 -Path $tmpFile).Hash.ToLowerInvariant()
+        $size = (Get-Item $tmpFile).Length
+
+        $lockedMods += [ordered]@{
+            source   = "curseforge"
+            slug     = $cf.slug
+            fileId   = $cf.fileId
+            version  = $cf.version
+            path     = $cf.path
+            url      = $cf.url
+            sha1     = $sha1
+            size     = $size
+        }
+        Write-Host ("  [cforge]  $($cf.slug.PadRight(22)) $($cf.version)")
+    }
+    catch {
+        Write-Warning "  [error]   $fname - $($_.Exception.Message)"
+        $missing += $fname
+    }
+}
+
+$lock = [ordered]@{
+    '$schema'   = "Brass-and-Sigil pack.lock.json - generated, do not edit by hand unless you know what you are doing"
+    name        = $PackName
+    version     = $PackVersion
+    minecraft   = $MinecraftVersion
+    loader      = [ordered]@{ type = $LoaderType; version = $LoaderVersion }
+    lockedAt    = (Get-Date -Format 'o')
+    mods        = $lockedMods
+}
+
+$json = $lock | ConvertTo-Json -Depth 10
+[System.IO.File]::WriteAllText($lockPath, $json, [System.Text.UTF8Encoding]::new($false))
+
+Write-Host ""
+Write-Host "Lockfile written: $lockPath"
+Write-Host ("  Total mods: {0}" -f $lockedMods.Count)
+if ($missing.Count -gt 0) {
+    Write-Warning "Missing: $($missing -join ', ')"
+}
+Write-Host ""
+Write-Host "Run Build-Pack.ps1 next to generate the manifest."

scripts/deploy.config.template.ps1

@@ -0,0 +1,37 @@
+# Local deploy configuration. Copy this file to `deploy.config.ps1` and fill in
+# real values. `deploy.config.ps1` is gitignored so your local paths and the
+# server hostname never end up in version control.
+#
+# Deploy-Brass.ps1 dot-sources this file. Every variable below is required.
+
+# ─── Public file hosting ───────────────────────────────────────────────────
+# Local path that maps (via SMB or similar) to the public docroot that hosts
+# `manifest.json` and the launcher .exe. Files copied here become reachable at
+# the public URLs embedded in the manifest (`launcherUrl`, file URLs, etc.).
+# Example: 'Z:\www\html\example.com\public\pack'
+$DeployShare       = 'CHANGE_ME'
+
+# Public URL of the deployed manifest. Used for the version-bump pre-flight:
+# Deploy-Brass.ps1 fetches this before deploying so it can refuse if you
+# changed pack content but forgot to bump pack/pack.lock.json's version
+# (clients with a cached pack at that version would skip the sync).
+$ManifestPublicUrl = 'https://CHANGE_ME/pack/manifest.json'
+
+# ─── Server (brass-sigil-server daemon host) ───────────────────────────────
+# user@host for the Linux box running the daemon.
+$ServerSshHost     = 'user@CHANGE_ME'
+
+# Path to the local SSH private key authorised on the server.
+$ServerSshKey      = "$env:USERPROFILE\.ssh\id_ed25519"
+
+# Absolute path on the Linux box where the brass-sigil-server binary lives.
+# `Deploy-Brass.ps1` uploads to "<this>.new" then `mv` over for atomic swap.
+$ServerBinaryRemote = '/home/user/brass-sigil-server/brass-sigil-server'
+
+# ─── Build outputs (don't normally need to change) ─────────────────────────
+$LauncherPublishDir = 'launcher\bin\Release\net8.0-windows\win-x64\publish'
+$LauncherExeName    = 'ModpackLauncher.exe'                # what dotnet publish produces
+$LauncherDeployedAs = 'BrassAndSigil-Launcher.exe'         # filename on the public host
+
+$ServerPublishDir   = 'server\bin\Release\net8.0\linux-x64\publish'
+$ServerExeName      = 'brass-sigil-server'

server/BrassAndSigilServer.csproj

@@ -0,0 +1,40 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <RootNamespace>BrassAndSigil.Server</RootNamespace>
+    <AssemblyName>brass-sigil-server</AssemblyName>
+    <ApplicationIcon>Assets\icon.ico</ApplicationIcon>
+
+    <!-- Single-file self-contained publish defaults -->
+    <RuntimeIdentifier Condition="'$(RuntimeIdentifier)' == ''">linux-x64</RuntimeIdentifier>
+    <RuntimeIdentifiers>linux-x64;win-x64</RuntimeIdentifiers>
+    <PublishSingleFile>true</PublishSingleFile>
+    <SelfContained>true</SelfContained>
+    <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
+    <EnableCompressionInSingleFile>true</EnableCompressionInSingleFile>
+    <DebugType>embedded</DebugType>
+
+    <!-- Embed wwwroot/* into the assembly so the published exe is truly single-file. -->
+    <GenerateEmbeddedFilesManifest>true</GenerateEmbeddedFilesManifest>
+    <StaticWebAssetsEnabled>false</StaticWebAssetsEnabled>
+    <IsTransformWebConfigDisabled>true</IsTransformWebConfigDisabled>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.FileProviders.Embedded" Version="10.0.7" />
+    <PackageReference Include="Spectre.Console.Cli" Version="0.49.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <!-- Replace the implicit Web SDK Content rule for wwwroot with EmbeddedResource. -->
+    <Content Remove="wwwroot\**" />
+    <EmbeddedResource Include="wwwroot\**" />
+    <!-- Server-list icon dropped into <serverDir>/server-icon.png on first install. -->
+    <EmbeddedResource Include="Assets\server-icon.png">
+      <LogicalName>BrassAndSigil.Server.Assets.server-icon.png</LogicalName>
+    </EmbeddedResource>
+  </ItemGroup>
+</Project>

server/Commands/BaseCommandSettings.cs

@@ -0,0 +1,11 @@
+using System.ComponentModel;
+using Spectre.Console.Cli;
+
+namespace BrassAndSigil.Server.Commands;
+
+public class BaseCommandSettings : CommandSettings
+{
+    [CommandOption("-c|--config <PATH>")]
+    [Description("Path to server-config.json (defaults to ./server-config.json)")]
+    public string ConfigPath { get; set; } = "server-config.json";
+}

server/Commands/CheckCommand.cs

@@ -0,0 +1,90 @@
+using System.Diagnostics;
+using BrassAndSigil.Server.Models;
+using BrassAndSigil.Server.Services;
+using Spectre.Console;
+using Spectre.Console.Cli;
+
+namespace BrassAndSigil.Server.Commands;
+
+public sealed class CheckCommand : AsyncCommand<BaseCommandSettings>
+{
+    public override async Task<int> ExecuteAsync(CommandContext context, BaseCommandSettings settings)
+    {
+        var config = ServerConfig.Load(settings.ConfigPath);
+        AnsiConsole.MarkupLine("[bold]Checking server install...[/]");
+        var ok = true;
+
+        // 1. Java available?
+        var javaVersion = await TryRunForOutputAsync(config.JavaPath, "-version");
+        if (javaVersion is not null)
+            AnsiConsole.MarkupLine($"  [green]✓[/] Java reachable: {javaVersion.Split('\n')[0].Trim().EscapeMarkup()}");
+        else
+        { AnsiConsole.MarkupLine($"  [red]✗[/] Java not found at '{config.JavaPath}'"); ok = false; }
+
+        // 2. Server dir
+        var serverDir = Path.GetFullPath(config.ServerDir);
+        if (Directory.Exists(serverDir))
+            AnsiConsole.MarkupLine($"  [green]✓[/] Server dir exists: {serverDir}");
+        else
+        { AnsiConsole.MarkupLine($"  [yellow]?[/] Server dir missing -- run [yellow]install[/] first"); ok = false; }
+
+        // 3. EULA
+        var eulaPath = Path.Combine(serverDir, "eula.txt");
+        if (File.Exists(eulaPath) && File.ReadAllText(eulaPath).Contains("eula=true"))
+            AnsiConsole.MarkupLine("  [green]✓[/] EULA accepted");
+        else
+        { AnsiConsole.MarkupLine("  [yellow]?[/] EULA not accepted (re-run [yellow]install --accept-eula[/])"); ok = false; }
+
+        // 4. NeoForge run script
+        var runScript = Path.Combine(serverDir, OperatingSystem.IsWindows() ? "run.bat" : "run.sh");
+        if (File.Exists(runScript))
+            AnsiConsole.MarkupLine($"  [green]✓[/] Loader start script: {Path.GetFileName(runScript)}");
+        else
+            AnsiConsole.MarkupLine($"  [yellow]?[/] No {Path.GetFileName(runScript)} -- install the NeoForge server first");
+
+        // 5. Manifest reachable
+        try
+        {
+            using var http = new HttpClient { Timeout = TimeSpan.FromSeconds(10) };
+            var resp = await http.GetAsync(config.ManifestUrl);
+            if (resp.IsSuccessStatusCode)
+                AnsiConsole.MarkupLine($"  [green]✓[/] Manifest reachable: {config.ManifestUrl}");
+            else
+            { AnsiConsole.MarkupLine($"  [red]✗[/] Manifest HTTP {(int)resp.StatusCode}: {config.ManifestUrl}"); ok = false; }
+        }
+        catch (Exception ex)
+        { AnsiConsole.MarkupLine($"  [red]✗[/] Manifest fetch error: {ex.Message.EscapeMarkup()}"); ok = false; }
+
+        // 6. Pack version on disk
+        var packVer = Path.Combine(serverDir, "pack-version.json");
+        if (File.Exists(packVer))
+            AnsiConsole.MarkupLine($"  [green]✓[/] Pack synced: {File.ReadAllText(packVer).Replace("\n", " ").Replace("\r", "").Trim().EscapeMarkup()}");
+        else
+            AnsiConsole.MarkupLine("  [yellow]?[/] Pack not synced yet (run [yellow]sync[/])");
+
+        AnsiConsole.MarkupLine("");
+        AnsiConsole.MarkupLine(ok ? "[green]All required checks passed.[/]" : "[yellow]Some checks failed; see above.[/]");
+        return ok ? 0 : 1;
+    }
+
+    private static async Task<string?> TryRunForOutputAsync(string fileName, string args)
+    {
+        try
+        {
+            var p = Process.Start(new ProcessStartInfo
+            {
+                FileName = fileName,
+                Arguments = args,
+                RedirectStandardOutput = true,
+                RedirectStandardError = true,
+                UseShellExecute = false,
+                CreateNoWindow = true,
+            });
+            if (p is null) return null;
+            var output = await p.StandardError.ReadToEndAsync() + await p.StandardOutput.ReadToEndAsync();
+            await p.WaitForExitAsync();
+            return output;
+        }
+        catch { return null; }
+    }
+}

server/Commands/InstallCommand.cs

@@ -0,0 +1,141 @@
+using System.ComponentModel;
+using BrassAndSigil.Server.Models;
+using BrassAndSigil.Server.Services;
+using Spectre.Console;
+using Spectre.Console.Cli;
+
+namespace BrassAndSigil.Server.Commands;
+
+public sealed class InstallCommand : AsyncCommand<InstallCommand.Settings>
+{
+    public sealed class Settings : BaseCommandSettings
+    {
+        [CommandOption("--manifest <URL>")]
+        [Description("Manifest URL to bootstrap from")]
+        public string? ManifestUrl { get; set; }
+
+        [CommandOption("--server-dir <PATH>")]
+        [Description("Where to install the server (defaults to ./server)")]
+        public string? ServerDir { get; set; }
+
+        [CommandOption("--memory <MB>")]
+        [Description("RAM allocation in MB (defaults to 8192)")]
+        public int? MemoryMB { get; set; }
+
+        [CommandOption("--accept-eula")]
+        [Description("Accept the Minecraft EULA. Required for the server to actually run.")]
+        public bool AcceptEula { get; set; }
+    }
+
+    public override async Task<int> ExecuteAsync(CommandContext context, Settings settings)
+    {
+        var config = ServerConfig.Load(settings.ConfigPath);
+        if (settings.ManifestUrl != null) config.ManifestUrl = settings.ManifestUrl;
+        if (settings.ServerDir   != null) config.ServerDir   = settings.ServerDir;
+        if (settings.MemoryMB    != null) config.MemoryMB    = settings.MemoryMB.Value;
+        if (settings.AcceptEula)          config.AcceptEula  = true;
+
+        AnsiConsole.MarkupLine("[bold yellow]Brass & Sigil Server install[/]");
+        AnsiConsole.MarkupLine($"  Config:    {settings.ConfigPath}");
+        AnsiConsole.MarkupLine($"  ServerDir: {Path.GetFullPath(config.ServerDir)}");
+        AnsiConsole.MarkupLine($"  Manifest:  {config.ManifestUrl}");
+        AnsiConsole.MarkupLine($"  Memory:    {config.MemoryMB} MB");
+        AnsiConsole.MarkupLine("");
+
+        if (!config.AcceptEula)
+        {
+            AnsiConsole.MarkupLine("[red]EULA not accepted.[/] Re-run with --accept-eula to confirm you accept the");
+            AnsiConsole.MarkupLine("Minecraft End User License Agreement: [blue]https://aka.ms/MinecraftEULA[/]");
+            return 1;
+        }
+
+        Directory.CreateDirectory(config.ServerDir);
+
+        // Generate eula.txt
+        await File.WriteAllTextAsync(
+            Path.Combine(config.ServerDir, "eula.txt"),
+            $"# Generated by brass-sigil-server install\n" +
+            $"# By setting this to true you agree to the Minecraft EULA: https://aka.ms/MinecraftEULA\n" +
+            $"eula=true\n");
+
+        // Generate a default server.properties if none exists yet
+        var propsPath = Path.Combine(config.ServerDir, "server.properties");
+        if (!File.Exists(propsPath))
+        {
+            await File.WriteAllTextAsync(propsPath, DefaultServerProperties(config));
+            AnsiConsole.MarkupLine($"[grey]Wrote default server.properties[/]");
+        }
+
+        // Generate a random RCON password if missing
+        if (string.IsNullOrEmpty(config.RconPassword))
+        {
+            config.RconPassword = Convert.ToHexString(Guid.NewGuid().ToByteArray()).ToLowerInvariant();
+            UpdateProp(propsPath, "enable-rcon", "true");
+            UpdateProp(propsPath, "rcon.port", config.RconPort.ToString());
+            UpdateProp(propsPath, "rcon.password", config.RconPassword);
+        }
+
+        // Save config
+        config.Save(settings.ConfigPath);
+        AnsiConsole.MarkupLine($"[grey]Saved config to {settings.ConfigPath}[/]");
+
+        // Sync mods
+        AnsiConsole.MarkupLine("");
+        AnsiConsole.MarkupLine("[bold]Syncing mods from manifest...[/]");
+        var sync = new ManifestSync();
+        var progress = new Progress<string>(msg => AnsiConsole.MarkupLine($"  [grey]{msg.EscapeMarkup()}[/]"));
+        try
+        {
+            var result = await sync.SyncAsync(config.ManifestUrl, config.ServerDir, progress);
+            AnsiConsole.MarkupLine("");
+            AnsiConsole.MarkupLine($"[green]✓ Sync complete:[/] pack v{result.PackVersion}, " +
+                                   $"{result.Downloaded} downloaded, {result.Removed} removed, " +
+                                   $"{result.Skipped} client-only mods skipped");
+        }
+        catch (Exception ex)
+        {
+            AnsiConsole.MarkupLine($"[red]✗ Sync failed:[/] {ex.Message.EscapeMarkup()}");
+            return 1;
+        }
+
+        AnsiConsole.MarkupLine("");
+        AnsiConsole.MarkupLine("[bold green]Install complete.[/]");
+        AnsiConsole.MarkupLine("Next steps:");
+        AnsiConsole.MarkupLine($"  1. Download the matching NeoForge server installer for the manifest's loader version");
+        AnsiConsole.MarkupLine($"     (server side, into {Path.GetFullPath(config.ServerDir)}) -- the modpack manifest");
+        AnsiConsole.MarkupLine($"     doesn't bundle it because each loader has its own installer.");
+        AnsiConsole.MarkupLine($"     [blue]https://maven.neoforged.net/releases/net/neoforged/neoforge/[/]");
+        AnsiConsole.MarkupLine($"  2. Run the NeoForge installer with --installServer in the server dir");
+        AnsiConsole.MarkupLine($"  3. Then start: [yellow]brass-sigil-server run[/]");
+        return 0;
+    }
+
+    private static string DefaultServerProperties(ServerConfig config) => $@"# Brass & Sigil server defaults -- edit as needed
+motd=Brass & Sigil
+gamemode=survival
+difficulty=normal
+hardcore=false
+pvp=true
+online-mode=true
+white-list=true
+enforce-whitelist=true
+max-players=20
+view-distance=12
+simulation-distance=10
+spawn-protection=0
+enable-rcon=true
+rcon.port={config.RconPort}
+rcon.password={config.RconPassword}
+broadcast-rcon-to-ops=false
+";
+
+    private static void UpdateProp(string path, string key, string value)
+    {
+        var lines = File.ReadAllLines(path).ToList();
+        var prefix = $"{key}=";
+        var idx = lines.FindIndex(l => l.StartsWith(prefix));
+        if (idx >= 0) lines[idx] = prefix + value;
+        else lines.Add(prefix + value);
+        File.WriteAllLines(path, lines);
+    }
+}

server/Commands/SetPasswordCommand.cs

@@ -0,0 +1,44 @@
+using BrassAndSigil.Server.Models;
+using Spectre.Console;
+using Spectre.Console.Cli;
+
+namespace BrassAndSigil.Server.Commands;
+
+/// <summary>
+/// Set or rotate the web panel admin password from the CLI.
+/// Useful when first-time-setting up before exposing the panel publicly,
+/// or rotating after a suspected leak without going through the panel UI.
+/// </summary>
+public sealed class SetPasswordCommand : Command<BaseCommandSettings>
+{
+    public override int Execute(CommandContext context, BaseCommandSettings settings)
+    {
+        var config = ServerConfig.Load(settings.ConfigPath);
+
+        if (Console.IsInputRedirected)
+        {
+            AnsiConsole.MarkupLine("[red]set-password requires an interactive terminal.[/]");
+            return 1;
+        }
+
+        AnsiConsole.MarkupLine("[bold]Set admin password[/]");
+        if (!string.IsNullOrEmpty(config.WebPassword))
+            AnsiConsole.MarkupLine("[grey]An existing password is already set; this will overwrite it.[/]");
+
+        string pw1, pw2;
+        while (true)
+        {
+            pw1 = AnsiConsole.Prompt(new TextPrompt<string>("New password (min 8 chars):").Secret());
+            if (pw1.Length < 8) { AnsiConsole.MarkupLine("[red]Too short.[/]"); continue; }
+            pw2 = AnsiConsole.Prompt(new TextPrompt<string>("Confirm:").Secret());
+            if (pw1 != pw2) { AnsiConsole.MarkupLine("[red]Doesn't match.[/]"); continue; }
+            break;
+        }
+
+        config.WebPassword = pw1;
+        config.Save(settings.ConfigPath);
+        AnsiConsole.MarkupLine($"[green]✓[/] Saved to {settings.ConfigPath}.");
+        AnsiConsole.MarkupLine("[grey]Restart the server for the new password to take effect.[/]");
+        return 0;
+    }
+}

server/Commands/SyncCommand.cs

@@ -0,0 +1,32 @@
+using BrassAndSigil.Server.Models;
+using BrassAndSigil.Server.Services;
+using Spectre.Console;
+using Spectre.Console.Cli;
+
+namespace BrassAndSigil.Server.Commands;
+
+public sealed class SyncCommand : AsyncCommand<BaseCommandSettings>
+{
+    public override async Task<int> ExecuteAsync(CommandContext context, BaseCommandSettings settings)
+    {
+        var config = ServerConfig.Load(settings.ConfigPath);
+        AnsiConsole.MarkupLine($"[bold]Syncing[/] from [blue]{config.ManifestUrl}[/]");
+        AnsiConsole.MarkupLine($"[grey]Target: {Path.GetFullPath(config.ServerDir)}[/]");
+        AnsiConsole.MarkupLine("");
+
+        var sync = new ManifestSync();
+        var progress = new Progress<string>(msg => AnsiConsole.MarkupLine($"  [grey]{msg.EscapeMarkup()}[/]"));
+        try
+        {
+            var result = await sync.SyncAsync(config.ManifestUrl, config.ServerDir, progress);
+            AnsiConsole.MarkupLine("");
+            AnsiConsole.MarkupLine($"[green]✓[/] pack v{result.PackVersion} | downloaded={result.Downloaded} removed={result.Removed} client-only-skipped={result.Skipped}");
+            return 0;
+        }
+        catch (Exception ex)
+        {
+            AnsiConsole.MarkupLine($"[red]✗[/] {ex.Message.EscapeMarkup()}");
+            return 1;
+        }
+    }
+}

server/Models/Manifest.cs

@@ -0,0 +1,62 @@
+using System.Text.Json.Serialization;
+
+namespace BrassAndSigil.Server.Models;
+
+public sealed class Manifest
+{
+    [JsonPropertyName("name")]
+    public string? Name { get; set; }
+
+    [JsonPropertyName("version")]
+    public string? Version { get; set; }
+
+    [JsonPropertyName("minecraft")]
+    public MinecraftSpec Minecraft { get; set; } = new();
+
+    [JsonPropertyName("loader")]
+    public LoaderSpec? Loader { get; set; }
+
+    [JsonPropertyName("files")]
+    public List<ManifestFile> Files { get; set; } = new();
+}
+
+public sealed class MinecraftSpec
+{
+    [JsonPropertyName("version")] public string Version { get; set; } = "";
+}
+
+public sealed class LoaderSpec
+{
+    [JsonPropertyName("type")]    public string Type    { get; set; } = "vanilla";
+    [JsonPropertyName("version")] public string Version { get; set; } = "";
+}
+
+public sealed class ManifestFile
+{
+    [JsonPropertyName("path")] public string  Path { get; set; } = "";
+    [JsonPropertyName("url")]  public string  Url  { get; set; } = "";
+    [JsonPropertyName("sha1")] public string? Sha1 { get; set; }
+    [JsonPropertyName("size")] public long?   Size { get; set; }
+}
+
+public sealed class PackLock
+{
+    [JsonPropertyName("name")]      public string  Name      { get; set; } = "";
+    [JsonPropertyName("version")]   public string  Version   { get; set; } = "";
+    [JsonPropertyName("minecraft")] public string  Minecraft { get; set; } = "";
+    [JsonPropertyName("loader")]    public LoaderSpec Loader { get; set; } = new();
+    [JsonPropertyName("mods")]      public List<LockedMod> Mods { get; set; } = new();
+}
+
+public sealed class LockedMod
+{
+    [JsonPropertyName("source")]    public string  Source    { get; set; } = "";
+    [JsonPropertyName("slug")]      public string? Slug      { get; set; }
+    [JsonPropertyName("versionId")] public string? VersionId { get; set; }
+    [JsonPropertyName("fileId")]    public string? FileId    { get; set; }
+    [JsonPropertyName("version")]   public string  Version   { get; set; } = "";
+    [JsonPropertyName("path")]      public string  Path      { get; set; } = "";
+    [JsonPropertyName("url")]       public string  Url       { get; set; } = "";
+    [JsonPropertyName("sha1")]      public string  Sha1      { get; set; } = "";
+    [JsonPropertyName("size")]      public long    Size      { get; set; }
+}

server/Models/ServerConfig.cs

@@ -0,0 +1,77 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using BrassAndSigil.Server.Services;
+
+namespace BrassAndSigil.Server.Models;
+
+public sealed class ServerConfig
+{
+    [JsonPropertyName("manifestUrl")]
+    public string ManifestUrl { get; set; } = "https://sijbers.uk/pack/manifest.json";
+
+    [JsonPropertyName("serverDir")]
+    public string ServerDir { get; set; } = "./server";
+
+    [JsonPropertyName("javaPath")]
+    public string JavaPath { get; set; } = "java";
+
+    [JsonPropertyName("memoryMB")]
+    public int MemoryMB { get; set; } = 8192;
+
+    [JsonPropertyName("webPort")]
+    public int WebPort { get; set; } = 8080;
+
+    /// <summary>"localhost" by default -- bind to 0.0.0.0 only behind a reverse proxy.</summary>
+    [JsonPropertyName("webHost")]
+    public string WebHost { get; set; } = "localhost";
+
+    /// <summary>Shared password for web UI. Required if WebHost is not localhost.</summary>
+    [JsonPropertyName("webPassword")]
+    public string? WebPassword { get; set; }
+
+    /// <summary>Where world backups land. Empty -> &lt;serverDir&gt;/../backups. Set to a
+    /// large/slower drive on real deployments -- backups grow over time.</summary>
+    [JsonPropertyName("backupDir")]
+    public string? BackupDir { get; set; }
+
+    /// <summary>Auto-rotation: keep this many most recent backups, delete older.</summary>
+    [JsonPropertyName("backupKeep")]
+    public int BackupKeep { get; set; } = 10;
+
+    /// <summary>Daily auto-backup time as "HH:mm" (24-hour, server-local). Null/empty disables.</summary>
+    [JsonPropertyName("backupSchedule")]
+    public string? BackupSchedule { get; set; }
+
+    /// <summary>
+    /// Where BlueMap CLI's working dir lives (cli.jar, configs, render output).
+    /// Empty -> alongside &lt;serverDir&gt;/.. (default ~/brass-sigil-server/bluemap).
+    /// Set to a big-disk path on real deployments -- rendered output for a 5000-block
+    /// world is several GB.
+    /// </summary>
+    [JsonPropertyName("bluemapDir")]
+    public string? BlueMapDir { get; set; }
+
+    [JsonPropertyName("rconPort")]
+    public int RconPort { get; set; } = 25575;
+
+    [JsonPropertyName("rconPassword")]
+    public string RconPassword { get; set; } = "";
+
+    [JsonPropertyName("acceptEula")]
+    public bool AcceptEula { get; set; } = false;
+
+    public static ServerConfig Load(string path)
+    {
+        if (!File.Exists(path)) return new ServerConfig();
+        var json = File.ReadAllText(path);
+        return JsonSerializer.Deserialize<ServerConfig>(json, JsonOpts.CaseInsensitive) ?? new ServerConfig();
+    }
+
+    public void Save(string path)
+    {
+        var dir = Path.GetDirectoryName(Path.GetFullPath(path));
+        if (!string.IsNullOrEmpty(dir) && !Directory.Exists(dir)) Directory.CreateDirectory(dir);
+        var json = JsonSerializer.Serialize(this, JsonOpts.Pretty);
+        File.WriteAllText(path, json);
+    }
+}

server/Program.cs

@@ -0,0 +1,52 @@
+using BrassAndSigil.Server.Commands;
+using Spectre.Console;
+using Spectre.Console.Cli;
+
+// Detect interactive double-click on Windows so we can hold the console open at exit
+// (otherwise the window vanishes before the user can read errors).
+var interactive = !Console.IsInputRedirected && OperatingSystem.IsWindows();
+
+var app = new CommandApp<RunCommand>();
+app.Configure(config =>
+{
+    config.SetApplicationName("brass-sigil-server");
+    config.SetApplicationVersion("0.1.0");
+
+    config.AddCommand<InstallCommand>("install")
+        .WithDescription("Force a fresh setup: download mods + run the NeoForge installer.");
+
+    config.AddCommand<SyncCommand>("sync")
+        .WithDescription("Update mods to match the current manifest. Server should be stopped first.");
+
+    config.AddCommand<RunCommand>("run")
+        .WithDescription("Run the server daemon (auto-installs anything missing, then serves the web UI).")
+        .WithAlias("start");
+
+    config.AddCommand<CheckCommand>("check")
+        .WithDescription("Verify install: dependencies, EULA, manifest reachability.");
+
+    config.AddCommand<SetPasswordCommand>("set-password")
+        .WithDescription("Set or rotate the web panel admin password.");
+});
+
+int result;
+try
+{
+    result = await app.RunAsync(args);
+}
+catch (Exception ex)
+{
+    AnsiConsole.WriteException(ex, ExceptionFormats.ShortenEverything);
+    result = 1;
+}
+
+// Hold the console open at exit only when an error occurred during interactive use.
+// Successful daemon termination (Ctrl+C, /api/server/stop) closes cleanly.
+if (interactive && result != 0)
+{
+    AnsiConsole.MarkupLine("");
+    AnsiConsole.MarkupLine("[grey]Press any key to close...[/]");
+    Console.ReadKey(intercept: true);
+}
+
+return result;

server/Services/BackupScheduler.cs

@@ -0,0 +1,202 @@
+using System.Text.RegularExpressions;
+using BrassAndSigil.Server.Models;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Auto-backup driven by config.BackupSchedule. Accepted formats:
+///   - "HH:mm"                 single daily slot (e.g. "04:00")
+///   - "HH:mm,HH:mm,..."       multiple daily slots
+///   - "every Nh"              every N hours (>= 15 minutes)
+///   - "every Nm"              every N minutes
+/// Wakes once a minute and fires backups when the clock matches the spec.
+/// Doesn't catch up if the server was off when a slot passed -- daily/interval
+/// backups don't need replay logic.
+/// </summary>
+public sealed class BackupScheduler : IDisposable
+{
+    private readonly ServerConfig _config;
+    private readonly BackupService _backup;
+    private readonly Action<string> _log;
+    private CancellationTokenSource? _cts;
+    private Task? _loop;
+
+    // Tracking for "fired" state. For interval: just the last fire time. For
+    // daily-times: which times have fired today, reset at day rollover.
+    private DateTimeOffset? _lastIntervalFire;
+    private DateOnly _lastFireDay = DateOnly.MinValue;
+    private readonly HashSet<TimeOnly> _firedToday = new();
+
+    public BackupScheduler(ServerConfig config, BackupService backup, Action<string> log)
+    {
+        _config = config;
+        _backup = backup;
+        _log    = log;
+    }
+
+    public void Start()
+    {
+        if (string.IsNullOrWhiteSpace(_config.BackupSchedule)) return;
+        if (Parse(_config.BackupSchedule) == default)
+        {
+            _log($"[backup-scheduler] Invalid backupSchedule '{_config.BackupSchedule}'. Expected 'HH:mm', 'HH:mm,HH:mm', or 'every Nh'/'every Nm'. Disabled.");
+            return;
+        }
+        _cts?.Cancel();
+        _cts = new CancellationTokenSource();
+        _loop = Task.Run(() => RunAsync(_cts.Token));
+        _log($"[backup-scheduler] Schedule active: {Describe()}");
+    }
+
+    /// <summary>Stop the current loop and re-Start with the latest config values.</summary>
+    public void Reload()
+    {
+        try { _cts?.Cancel(); _loop?.Wait(TimeSpan.FromSeconds(2)); } catch { }
+        _cts?.Dispose();
+        _cts = null;
+        _loop = null;
+        Start();
+    }
+
+    /// <summary>Compute the next future scheduled fire time. Null if no schedule.</summary>
+    public DateTimeOffset? NextRun()
+    {
+        var (interval, times) = Parse(_config.BackupSchedule);
+        if (interval.HasValue)
+        {
+            var baseTime = _lastIntervalFire ?? DateTimeOffset.UtcNow.AddSeconds(-1);
+            var next = baseTime + interval.Value;
+            // If we've never fired and we're past the implied first slot, "next" might be
+            // in the past -- clamp to "imminent" by using now + small buffer.
+            if (next <= DateTimeOffset.UtcNow) next = DateTimeOffset.UtcNow.AddMinutes(1);
+            return next.ToLocalTime();
+        }
+        if (times is not null)
+        {
+            var now = DateTime.Now;
+            var nowTime = TimeOnly.FromDateTime(now);
+            // Use Cast<TimeOnly?>().FirstOrDefault() so "no pending" is null rather than 00:00.
+            var pendingToday = times
+                .Where(t => t > nowTime && !_firedToday.Contains(t))
+                .OrderBy(t => t)
+                .Cast<TimeOnly?>()
+                .FirstOrDefault();
+            if (pendingToday.HasValue)
+                return new DateTimeOffset(now.Date.Add(pendingToday.Value.ToTimeSpan()));
+            // None left today -- first slot tomorrow.
+            var firstTomorrow = times.Min();
+            return new DateTimeOffset(now.Date.AddDays(1).Add(firstTomorrow.ToTimeSpan()));
+        }
+        return null;
+    }
+
+    private async Task RunAsync(CancellationToken ct)
+    {
+        while (!ct.IsCancellationRequested)
+        {
+            try { await Task.Delay(TimeSpan.FromMinutes(1), ct); }
+            catch (OperationCanceledException) { break; }
+
+            var (interval, times) = Parse(_config.BackupSchedule);
+            if (interval is null && times is null) continue;
+
+            var nowUtc   = DateTimeOffset.UtcNow;
+            var nowLocal = DateTime.Now;
+            var today    = DateOnly.FromDateTime(nowLocal);
+            var nowTime  = TimeOnly.FromDateTime(nowLocal);
+
+            bool shouldFire = false;
+            if (interval.HasValue)
+            {
+                shouldFire = !_lastIntervalFire.HasValue
+                          || (nowUtc - _lastIntervalFire.Value) >= interval.Value;
+            }
+            else if (times is not null)
+            {
+                if (today != _lastFireDay)
+                {
+                    _firedToday.Clear();
+                    _lastFireDay = today;
+                }
+                foreach (var t in times)
+                {
+                    if (t <= nowTime && !_firedToday.Contains(t))
+                    {
+                        shouldFire = true;
+                        _firedToday.Add(t);
+                        break;
+                    }
+                }
+            }
+
+            if (!shouldFire) continue;
+
+            _log("[backup-scheduler] Triggering scheduled backup.");
+            try
+            {
+                var result = await _backup.CreateAsync("scheduled", ct: ct);
+                if (result.Ok) _log($"[backup-scheduler] Done: {result.Name} ({result.SizeBytes / (1024 * 1024)} MB).");
+                else           _log($"[backup-scheduler] Failed: {result.Error}");
+                if (interval.HasValue) _lastIntervalFire = nowUtc;
+            }
+            catch (OperationCanceledException) { break; }
+            catch (Exception ex) { _log($"[backup-scheduler] Exception: {ex.Message}"); }
+        }
+    }
+
+    /// <summary>Returns (interval, times) -- exactly one will be non-null on success, or (null,null) for invalid/empty.</summary>
+    private static (TimeSpan? Interval, TimeOnly[]? Times) Parse(string? input)
+    {
+        if (string.IsNullOrWhiteSpace(input)) return (null, null);
+        var s = input.Trim().ToLowerInvariant();
+
+        // every Nh / every Nm
+        var m = Regex.Match(s, @"^every\s+(\d+)\s*(h|hr|hrs|hour|hours|m|min|mins|minute|minutes)$");
+        if (m.Success)
+        {
+            var n = int.Parse(m.Groups[1].Value);
+            var unit = m.Groups[2].Value;
+            var span = unit.StartsWith("h") ? TimeSpan.FromHours(n) : TimeSpan.FromMinutes(n);
+            // Sanity floor -- anything below 15 min creates more save-lag than backups are worth.
+            if (span < TimeSpan.FromMinutes(15)) return (null, null);
+            if (span > TimeSpan.FromDays(7))    return (null, null);
+            return (span, null);
+        }
+
+        // Comma-separated HH:mm
+        var list = new List<TimeOnly>();
+        foreach (var tok in s.Split(',', StringSplitOptions.RemoveEmptyEntries))
+        {
+            if (!TimeOnly.TryParse(tok.Trim(), out var t)) return (null, null);
+            list.Add(t);
+        }
+        return list.Count == 0 ? (null, null) : (null, list.OrderBy(t => t).ToArray());
+    }
+
+    public string Describe()
+    {
+        var (interval, times) = Parse(_config.BackupSchedule);
+        if (interval.HasValue)
+        {
+            var totalMin = (int)interval.Value.TotalMinutes;
+            if (totalMin >= 60 && totalMin % 60 == 0)
+            {
+                var h = totalMin / 60;
+                return h == 1 ? "Every hour" : $"Every {h} hours";
+            }
+            return totalMin == 1 ? "Every minute" : $"Every {totalMin} minutes";
+        }
+        if (times is not null)
+        {
+            if (times.Length == 1) return $"Daily at {times[0]:HH\\:mm}";
+            return "Daily at " + string.Join(", ", times.Select(t => t.ToString("HH:mm")));
+        }
+        return "Disabled";
+    }
+
+    public void Dispose()
+    {
+        try { _cts?.Cancel(); _loop?.Wait(TimeSpan.FromSeconds(2)); } catch { }
+        _cts?.Dispose();
+    }
+}

server/Services/BackupService.cs

@@ -0,0 +1,257 @@
+using System.IO.Compression;
+using BrassAndSigil.Server.Models;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// World backups: ZIP the level-name dir into a separate (typically slower-but-bigger)
+/// backup directory. Online backups via /save-all flush + /save-off while the server is
+/// running mean players don't see downtime -- just a brief save lag.
+/// </summary>
+public sealed class BackupService
+{
+    private readonly ServerConfig _config;
+    private readonly ServerProcess _proc;
+    private readonly Broadcaster _broadcast;
+    private readonly Action<string> _log;
+    private readonly SemaphoreSlim _gate = new(1, 1);
+
+    public BackupService(ServerConfig config, ServerProcess proc, Broadcaster broadcast, Action<string> log)
+    {
+        _config    = config;
+        _proc      = proc;
+        _broadcast = broadcast;
+        _log       = log;
+    }
+
+    public sealed record BackupInfo(string Name, long SizeBytes, DateTimeOffset CreatedAt);
+    public sealed record CreateResult(bool Ok, string? Name, long SizeBytes, string? Error);
+
+    public string BackupDir => ResolveBackupDir();
+
+    public List<BackupInfo> List()
+    {
+        var dir = BackupDir;
+        if (!Directory.Exists(dir)) return new();
+        return Directory.EnumerateFiles(dir, "*.zip")
+            .Select(p =>
+            {
+                var fi = new FileInfo(p);
+                return new BackupInfo(fi.Name, fi.Length, new DateTimeOffset(fi.CreationTimeUtc, TimeSpan.Zero));
+            })
+            .OrderByDescending(b => b.CreatedAt)
+            .ToList();
+    }
+
+    /// <summary>
+    /// Create a ZIP backup of the world dir. Online (no shutdown) when the server is
+    /// running.
+    /// <para>
+    /// <paramref name="flush"/> = false (default): just <c>save-off</c> + brief drain +
+    /// ZIP + <c>save-on</c>. Near-zero player-visible lag. Backup captures state up to
+    /// MC's last autosave (within ~5 min) -- fine for hourly snapshots.
+    /// </para>
+    /// <para>
+    /// <paramref name="flush"/> = true: also runs <c>save-all flush</c> first, which
+    /// synchronously serialises every loaded chunk before the ZIP. Captures state up
+    /// to NOW. Causes a tick spike of seconds-to-tens-of-seconds depending on world
+    /// size. Used only for irreversible operations (pre-wipe) where freshness matters.
+    /// </para>
+    /// </summary>
+    public async Task<CreateResult> CreateAsync(string? reason = null, bool flush = false, CancellationToken ct = default)
+    {
+        if (!await _gate.WaitAsync(0, ct))
+            return new CreateResult(false, null, 0, "Another backup is already in progress.");
+
+        var dir = ResolveBackupDir();
+        try
+        {
+            Directory.CreateDirectory(dir);
+        }
+        catch (Exception ex)
+        {
+            _gate.Release();
+            return new CreateResult(false, null, 0, $"Couldn't create backup dir '{dir}': {ex.Message}");
+        }
+
+        var levelName = ReadLevelName(_config.ServerDir) ?? "world";
+        var worldDir = Path.Combine(_config.ServerDir, levelName);
+        if (!Directory.Exists(worldDir))
+        {
+            _gate.Release();
+            return new CreateResult(false, null, 0, $"World directory not found at '{worldDir}'.");
+        }
+
+        var stamp = DateTime.UtcNow.ToString("yyyyMMdd-HHmmss");
+        var slug = string.IsNullOrWhiteSpace(reason) ? "" : "-" + Slugify(reason);
+        var name = $"{levelName}-{stamp}{slug}.zip";
+        var path = Path.Combine(dir, name);
+
+        var serverRunning = _proc.IsRunning;
+        try
+        {
+            if (serverRunning)
+            {
+                if (flush)
+                {
+                    // Loud path: fresh state, but pays the tick spike. Tell players.
+                    try { await _broadcast.SayAsync("Saving world for backup (brief lag possible)...", ct); } catch { }
+                    _log("[backup] save-all flush");
+                    await _proc.SendInputAsync("save-all flush", ct);
+                    await Task.Delay(2500, ct);
+                }
+                _log("[backup] save-off");
+                await _proc.SendInputAsync("save-off", ct);
+                // Brief drain so any save tasks already enqueued can finish before we
+                // start reading from disk for the ZIP.
+                await Task.Delay(500, ct);
+            }
+
+            _log($"[backup] Archiving {worldDir} -> {name}");
+            // Run on a worker thread so the request thread doesn't block on disk I/O.
+            await Task.Run(() =>
+                ZipFile.CreateFromDirectory(worldDir, path, CompressionLevel.Fastest, includeBaseDirectory: false), ct);
+
+            var size = new FileInfo(path).Length;
+            _log($"[backup] Created {name} ({size / (1024 * 1024)} MB).");
+            // No completion broadcast for silent path -- backup was invisible to players,
+            // no need to tell them it finished. Loud path is wipe-only and the wipe
+            // sequence has its own messaging.
+
+            RotateOldest(dir, _config.BackupKeep);
+
+            return new CreateResult(true, name, size, null);
+        }
+        catch (Exception ex)
+        {
+            _log($"[backup] Failed: {ex.Message}");
+            try { File.Delete(path); } catch { } // partial archive
+            return new CreateResult(false, null, 0, ex.Message);
+        }
+        finally
+        {
+            try
+            {
+                if (serverRunning && _proc.IsRunning)
+                {
+                    _log("[backup] save-on");
+                    await _proc.SendInputAsync("save-on");
+                }
+            }
+            catch { }
+            _gate.Release();
+        }
+    }
+
+    /// <summary>
+    /// Stop the server, move the current world out of the way as a "pre-restore" safety
+    /// copy, extract the chosen archive, restart.
+    /// </summary>
+    public async Task<(bool Ok, string? Error)> RestoreAsync(string backupName, CancellationToken ct = default)
+    {
+        if (!await _gate.WaitAsync(0, ct))
+            return (false, "Another backup operation is already in progress.");
+
+        try
+        {
+            var dir = ResolveBackupDir();
+            var path = Path.Combine(dir, Path.GetFileName(backupName));
+            if (!File.Exists(path)) return (false, $"Backup '{backupName}' not found.");
+
+            var levelName = ReadLevelName(_config.ServerDir) ?? "world";
+            var worldDir = Path.Combine(_config.ServerDir, levelName);
+
+            if (_proc.IsRunning)
+            {
+                _log("[restore] Stopping server before restore...");
+                await _proc.StopAsync(TimeSpan.FromSeconds(30), ct);
+            }
+
+            // Always preserve the current world as a pre-restore snapshot in case the
+            // chosen archive is corrupt or wrong.
+            if (Directory.Exists(worldDir))
+            {
+                var preRestore = $"{worldDir}-prerestore-{DateTime.UtcNow:yyyyMMddHHmmss}";
+                _log($"[restore] Moving current world to {Path.GetFileName(preRestore)}");
+                Directory.Move(worldDir, preRestore);
+            }
+
+            _log($"[restore] Extracting {backupName}");
+            Directory.CreateDirectory(worldDir);
+            await Task.Run(() => ZipFile.ExtractToDirectory(path, worldDir, overwriteFiles: true), ct);
+
+            _log("[restore] Starting server.");
+            _proc.Start();
+            return (true, null);
+        }
+        catch (Exception ex)
+        {
+            _log($"[restore] Failed: {ex.Message}");
+            try { if (!_proc.IsRunning) _proc.Start(); } catch { }
+            return (false, ex.Message);
+        }
+        finally
+        {
+            _gate.Release();
+        }
+    }
+
+    public (bool Ok, string? Error) Delete(string backupName)
+    {
+        try
+        {
+            var path = Path.Combine(ResolveBackupDir(), Path.GetFileName(backupName));
+            if (!File.Exists(path)) return (false, $"Backup '{backupName}' not found.");
+            File.Delete(path);
+            return (true, null);
+        }
+        catch (Exception ex) { return (false, ex.Message); }
+    }
+
+    private string ResolveBackupDir()
+    {
+        if (!string.IsNullOrWhiteSpace(_config.BackupDir))
+            return Path.GetFullPath(_config.BackupDir);
+        // Default: sibling of serverDir so it survives server-dir wipes.
+        var serverFull = Path.GetFullPath(_config.ServerDir);
+        var parent = Path.GetDirectoryName(serverFull) ?? serverFull;
+        return Path.Combine(parent, "backups");
+    }
+
+    private static void RotateOldest(string dir, int keep)
+    {
+        if (keep <= 0) return;
+        try
+        {
+            var zips = Directory.EnumerateFiles(dir, "*.zip")
+                .Select(p => new FileInfo(p))
+                .OrderByDescending(fi => fi.CreationTimeUtc)
+                .ToList();
+            foreach (var old in zips.Skip(keep))
+            {
+                try { old.Delete(); }
+                catch { /* best-effort */ }
+            }
+        }
+        catch { }
+    }
+
+    private static string? ReadLevelName(string serverDir)
+    {
+        var path = Path.Combine(serverDir, "server.properties");
+        if (!File.Exists(path)) return null;
+        foreach (var line in File.ReadAllLines(path))
+        {
+            if (line.StartsWith("level-name=", StringComparison.Ordinal))
+                return line.Substring("level-name=".Length).Trim();
+        }
+        return null;
+    }
+
+    private static string Slugify(string s)
+    {
+        var chars = s.Where(c => char.IsLetterOrDigit(c) || c == '-' || c == '_').ToArray();
+        var slug = new string(chars).ToLowerInvariant();
+        return slug.Length > 32 ? slug.Substring(0, 32) : slug;
+    }
+}

server/Services/BlueMapPlayers.cs

@@ -0,0 +1,145 @@
+using System.Globalization;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// On-demand snapshot of online players + positions, formatted for BlueMap's
+/// live player overlay. Pull-based: the BlueMap web UI polls a JSON file at
+/// <c>/map/maps/overworld/live/players.json</c> roughly every 2 s, and the
+/// daemon intercepts that path and calls <see cref="SnapshotAsync"/> per
+/// request. Closed tab = no requests = no RCON calls -- same model as
+/// <c>/api/players</c>, no server-side timer to manage.
+/// </summary>
+public static class BlueMapPlayers
+{
+    public static async Task<List<object>> SnapshotAsync(RconManager rcon, string serverDir, CancellationToken ct)
+    {
+        var listResp = await rcon.SendCommandAsync("list", ct);
+        // Format: "There are N of a max of M players online: name1, name2, ..."
+        var colon = listResp.IndexOf(':');
+        var names = colon < 0
+            ? Array.Empty<string>()
+            : listResp.Substring(colon + 1)
+                      .Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+        var result = new List<object>();
+        foreach (var name in names)
+        {
+            ct.ThrowIfCancellationRequested();
+            try
+            {
+                var posResp = await rcon.SendCommandAsync($"data get entity {name} Pos", ct);
+                var pos = ParseDoubleTriple(posResp);
+                if (pos is null) continue;
+                var rotResp = await rcon.SendCommandAsync($"data get entity {name} Rotation", ct);
+                var rot = ParseFloatPair(rotResp);
+
+                result.Add(new
+                {
+                    uuid     = ResolveUuid(serverDir, name),
+                    name,
+                    foreign  = false,
+                    position = new { x = pos.Value.x, y = pos.Value.y, z = pos.Value.z },
+                    rotation = new { pitch = rot?.pitch ?? 0, yaw = rot?.yaw ?? 0, roll = 0.0 },
+                });
+            }
+            catch
+            {
+                // One bad player shouldn't drop the rest of the list.
+            }
+        }
+        return result;
+    }
+
+    // ── UUID resolution ──────────────────────────────────────────────────────
+    // BlueMap uses the UUID for two things: marker identity across polls (so a
+    // changing UUID makes the marker flash on/off as it thinks the player keeps
+    // leaving and rejoining) and skin lookup against Mojang's profile API. We
+    // need the *real* Mojang UUID to satisfy both -- MC writes name→uuid pairs
+    // into <serverDir>/usercache.json after each successful auth. We cache that
+    // file's contents in memory and reload on mtime change, since usercache
+    // updates rarely (player join, periodic refresh).
+    private sealed class UserCacheEntry
+    {
+        public string? Name { get; set; }
+        public string? Uuid { get; set; }
+    }
+
+    private static readonly object _cacheLock = new();
+    private static Dictionary<string, string>? _cache;     // case-insensitive name → uuid
+    private static DateTime _cacheLoadedAt = DateTime.MinValue;
+    private static string? _cachePath;
+
+    private static string ResolveUuid(string serverDir, string name)
+    {
+        var path = Path.Combine(Path.GetFullPath(serverDir), "usercache.json");
+        lock (_cacheLock)
+        {
+            if (File.Exists(path))
+            {
+                var mtime = File.GetLastWriteTimeUtc(path);
+                if (_cache is null || _cachePath != path || mtime > _cacheLoadedAt)
+                {
+                    try
+                    {
+                        var json = File.ReadAllText(path);
+                        var entries = JsonSerializer.Deserialize<UserCacheEntry[]>(json, JsonOpts.CaseInsensitive);
+                        var dict = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+                        if (entries is not null)
+                            foreach (var e in entries)
+                                if (!string.IsNullOrEmpty(e.Name) && !string.IsNullOrEmpty(e.Uuid))
+                                    dict[e.Name] = e.Uuid;
+                        _cache = dict;
+                        _cachePath = path;
+                        _cacheLoadedAt = mtime;
+                    }
+                    catch
+                    {
+                        // Corrupt usercache shouldn't take down the marker -- fall through.
+                    }
+                }
+            }
+            if (_cache is not null && _cache.TryGetValue(name, out var uuid)) return uuid;
+        }
+
+        // Fallback when usercache hasn't been written yet (very early after
+        // first auth) or has been wiped: deterministic UUID derived from the
+        // name. Stable across polls so the marker doesn't flash; skin lookup
+        // will 404 against Mojang and BlueMap will show a default head.
+        return DeriveStableUuid(name).ToString();
+    }
+
+    private static Guid DeriveStableUuid(string name)
+    {
+        var bytes = SHA1.HashData(Encoding.UTF8.GetBytes("brass-sigil:" + name.ToLowerInvariant()));
+        var guidBytes = new byte[16];
+        Array.Copy(bytes, guidBytes, 16);
+        return new Guid(guidBytes);
+    }
+
+    // Parse a NBT-style double triple like "[123.4d, 64.0d, -56.7d]" out of an
+    // RCON `data get` response.
+    private static (double x, double y, double z)? ParseDoubleTriple(string resp)
+    {
+        var m = Regex.Match(resp, @"\[([\-\d\.]+)d?,\s*([\-\d\.]+)d?,\s*([\-\d\.]+)d?\]");
+        if (!m.Success) return null;
+        if (!double.TryParse(m.Groups[1].Value, NumberStyles.Float, CultureInfo.InvariantCulture, out var x)) return null;
+        if (!double.TryParse(m.Groups[2].Value, NumberStyles.Float, CultureInfo.InvariantCulture, out var y)) return null;
+        if (!double.TryParse(m.Groups[3].Value, NumberStyles.Float, CultureInfo.InvariantCulture, out var z)) return null;
+        return (x, y, z);
+    }
+
+    // Rotation comes as `[yaw, pitch]` in floats.
+    private static (double pitch, double yaw)? ParseFloatPair(string resp)
+    {
+        var m = Regex.Match(resp, @"\[([\-\d\.]+)f?,\s*([\-\d\.]+)f?\]");
+        if (!m.Success) return null;
+        if (!double.TryParse(m.Groups[1].Value, NumberStyles.Float, CultureInfo.InvariantCulture, out var yaw))   return null;
+        if (!double.TryParse(m.Groups[2].Value, NumberStyles.Float, CultureInfo.InvariantCulture, out var pitch)) return null;
+        return (pitch, yaw);
+    }
+}

server/Services/BlueMapService.cs

@@ -0,0 +1,321 @@
+using System.Diagnostics;
+using BrassAndSigil.Server.Models;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Wraps BlueMap CLI as an out-of-process renderer.
+///
+/// The CLI jar is downloaded from GitHub releases on first render (mirrors the
+/// JavaInstaller pattern -- keeps the brass-sigil-server binary lean and lets
+/// BlueMap update independently). BlueMap 5.20+ requires Java 25, so we also
+/// auto-install Adoptium Temurin JRE 25 alongside the JRE 21 we use for MC.
+///
+/// Renders are kicked off manually from the panel and produce static HTML/JS/PNG
+/// output served at /map/. Zero impact on the running MC server (separate JVM,
+/// separate memory pool -- only competes for disk I/O during render).
+/// </summary>
+public sealed class BlueMapService : IDisposable
+{
+    private const string BlueMapVersion = "5.20";
+    private const string BlueMapJarUrl =
+        "https://github.com/BlueMap-Minecraft/BlueMap/releases/download/v"
+      + BlueMapVersion + "/bluemap-" + BlueMapVersion + "-cli.jar";
+    private const int BlueMapJavaVersion = 25;
+    private static readonly HttpClient _http = new() { Timeout = TimeSpan.FromMinutes(10) };
+
+    private readonly ServerConfig _config;
+    private readonly Action<string> _log;
+    private readonly SemaphoreSlim _gate = new(1, 1);
+
+    private Process? _renderProc;
+    public sealed class RenderState
+    {
+        public bool InProgress       { get; set; }
+        public string Phase          { get; set; } = "idle";
+            // "idle" | "extracting" | "configuring" | "rendering" | "complete" | "failed"
+        public string? Error         { get; set; }
+        public DateTimeOffset? StartedAt  { get; set; }
+        public DateTimeOffset? FinishedAt { get; set; }
+        public int? ExitCode         { get; set; }
+        public string? LastLogLine   { get; set; }
+    }
+    public RenderState State { get; private set; } = new();
+
+    public string RootDir
+    {
+        get
+        {
+            // Configured override (e.g. /mnt/md0p1/brass-sigil/bluemap) wins. Default
+            // is sibling of serverDir so it doesn't bloat the world dir or the
+            // server install -- typically ~/brass-sigil-server/bluemap.
+            if (!string.IsNullOrWhiteSpace(_config.BlueMapDir))
+                return Path.GetFullPath(_config.BlueMapDir);
+            var serverFull = Path.GetFullPath(_config.ServerDir);
+            var parent = Path.GetDirectoryName(serverFull) ?? serverFull;
+            return Path.Combine(parent, "bluemap");
+        }
+    }
+    public string CliJarPath    => Path.Combine(RootDir, "cli.jar");
+    public string WebDir        => Path.Combine(RootDir, "web");
+    public string ConfigDir     => Path.Combine(RootDir, "config");
+
+    public BlueMapService(ServerConfig config, Action<string> log)
+    {
+        _config = config;
+        _log    = log;
+    }
+
+    public bool HasRendered => Directory.Exists(WebDir) &&
+                               File.Exists(Path.Combine(WebDir, "index.html"));
+
+    /// <summary>Kick off a render in the background. Returns false if one is already running.</summary>
+    public bool StartRender()
+    {
+        if (!_gate.Wait(0)) return false;
+        State = new RenderState { InProgress = true, Phase = "extracting", StartedAt = DateTimeOffset.UtcNow };
+        _ = Task.Run(RenderAsync);
+        return true;
+    }
+
+    /// <summary>
+    /// Cancel an in-progress render by killing the BlueMap process. State on disk
+    /// is preserved, so the next render resumes from where this one stopped.
+    /// </summary>
+    public bool CancelRender()
+    {
+        if (!State.InProgress) return false;
+        try
+        {
+            // Kill the whole process tree (the BlueMap CLI may spawn worker JVMs
+            // for parallel rendering). entireProcessTree=true on Linux uses
+            // process group; on Windows it walks the tree via Job Objects.
+            _renderProc?.Kill(entireProcessTree: true);
+            State.Phase = "cancelled";
+            State.Error = "Cancelled by user.";
+            _log("[bluemap] Render cancelled by user.");
+            return true;
+        }
+        catch (Exception ex)
+        {
+            _log($"[bluemap] Cancel failed: {ex.Message}");
+            return false;
+        }
+    }
+
+    /// <summary>
+    /// Delete rendered map output + render state. Used after a world wipe -- the
+    /// old tiles reference terrain that no longer exists. Preserves cli.jar and
+    /// configs so a follow-up Render still works (and skips re-download +
+    /// re-config). Returns true if anything was deleted.
+    /// </summary>
+    public bool ClearRenderOutput()
+    {
+        var dataDir = Path.Combine(RootDir, "data");
+        var mapsDir = Path.Combine(RootDir, "web", "maps");
+        var anyDeleted = false;
+        try
+        {
+            if (Directory.Exists(dataDir)) { Directory.Delete(dataDir, true); anyDeleted = true; _log("[bluemap] Cleared render state."); }
+            if (Directory.Exists(mapsDir)) { Directory.Delete(mapsDir, true); anyDeleted = true; _log("[bluemap] Cleared rendered tiles."); }
+        }
+        catch (Exception ex) { _log($"[bluemap] Couldn't clear output: {ex.Message}"); }
+        return anyDeleted;
+    }
+
+    /// <summary>
+    /// Called when brass-sigil-server itself shuts down -- kill any in-flight
+    /// BlueMap process so it doesn't orphan to PID 1 and keep eating CPU after
+    /// the daemon's gone. Render state on disk is preserved; next start can
+    /// resume the render exactly where this one was killed.
+    /// </summary>
+    public void Dispose()
+    {
+        try
+        {
+            if (_renderProc is { HasExited: false })
+            {
+                _renderProc.Kill(entireProcessTree: true);
+                _renderProc.WaitForExit(2000);
+            }
+        }
+        catch { }
+        _renderProc?.Dispose();
+        _gate.Dispose();
+    }
+
+    private async Task RenderAsync()
+    {
+        try
+        {
+            Directory.CreateDirectory(RootDir);
+
+            State.Phase = "downloading";
+            await DownloadJarIfMissingAsync();
+
+            // BlueMap 5.20 needs Java 25; our MC server runs Java 21. Maintain a
+            // separate JRE 25 install for BlueMap only.
+            var bluemapJava = await EnsureJava25Async();
+            if (bluemapJava is null) throw new InvalidOperationException("Couldn't install JRE 25 for BlueMap.");
+
+            // First run: BlueMap with no config writes default configs and exits.
+            // We need to (a) run it once to seed configs, (b) patch the world path,
+            // (c) re-run with -r to actually render.
+            State.Phase = "configuring";
+            EnsureConfig(bluemapJava);
+
+            State.Phase = "rendering";
+            // -r = render. --mods <modsDir> = pull textures from mod jars so Create
+            // blocks etc. show real colours instead of magenta/grey fallback.
+            var modsDir = Path.Combine(Path.GetFullPath(_config.ServerDir), "mods");
+            var args = new List<string> { "-jar", CliJarPath, "-r" };
+            if (Directory.Exists(modsDir))
+            {
+                args.Add("--mods");
+                args.Add(modsDir);
+            }
+
+            var psi = new ProcessStartInfo
+            {
+                FileName = bluemapJava,
+                WorkingDirectory = RootDir,
+                UseShellExecute = false,
+                RedirectStandardOutput = true,
+                RedirectStandardError = true,
+                CreateNoWindow = true,
+            };
+            foreach (var a in args) psi.ArgumentList.Add(a);
+
+            _renderProc = new Process { StartInfo = psi, EnableRaisingEvents = true };
+            _renderProc.OutputDataReceived += (_, e) => { if (e.Data is { } line) { State.LastLogLine = line; _log($"[bluemap] {line}"); } };
+            _renderProc.ErrorDataReceived  += (_, e) => { if (e.Data is { } line) { State.LastLogLine = line; _log($"[bluemap] {line}"); } };
+
+            _renderProc.Start();
+            _renderProc.BeginOutputReadLine();
+            _renderProc.BeginErrorReadLine();
+            await _renderProc.WaitForExitAsync();
+
+            State.ExitCode = _renderProc.ExitCode;
+            State.FinishedAt = DateTimeOffset.UtcNow;
+            if (_renderProc.ExitCode == 0) State.Phase = "complete";
+            else { State.Phase = "failed"; State.Error = $"BlueMap exited with code {_renderProc.ExitCode}"; }
+        }
+        catch (Exception ex)
+        {
+            State.Phase = "failed";
+            State.Error = ex.Message;
+            State.FinishedAt = DateTimeOffset.UtcNow;
+            _log($"[bluemap] Failed: {ex.Message}");
+        }
+        finally
+        {
+            State.InProgress = false;
+            _renderProc?.Dispose();
+            _renderProc = null;
+            _gate.Release();
+        }
+    }
+
+    private async Task DownloadJarIfMissingAsync()
+    {
+        if (File.Exists(CliJarPath)) return;
+        _log($"[bluemap] Downloading BlueMap CLI v{BlueMapVersion} to {CliJarPath}");
+        Directory.CreateDirectory(Path.GetDirectoryName(CliJarPath)!);
+        using var resp = await _http.GetAsync(BlueMapJarUrl, HttpCompletionOption.ResponseHeadersRead);
+        resp.EnsureSuccessStatusCode();
+        await using var src = await resp.Content.ReadAsStreamAsync();
+        await using var dst = File.Create(CliJarPath);
+        await src.CopyToAsync(dst);
+        _log($"[bluemap] Downloaded {new FileInfo(CliJarPath).Length / 1024} KB.");
+    }
+
+    /// <summary>Reuse JavaInstaller to drop a JRE 25 next to JRE 21 (separate dirs).</summary>
+    private async Task<string?> EnsureJava25Async()
+    {
+        var installer = new JavaInstaller();
+        var serverFull = Path.GetFullPath(_config.ServerDir);
+        // Look for an existing JRE 25 install first (idempotent across renders).
+        var existing = installer.FindBundledJava(serverFull, BlueMapJavaVersion);
+        if (existing is not null) return existing;
+        var installDir = installer.GetJavaInstallDir(serverFull, BlueMapJavaVersion);
+        var progress = new Progress<string>(msg => _log("[bluemap] " + msg));
+        return await installer.InstallJreAsync(BlueMapJavaVersion, serverFull, installDir, progress, default);
+    }
+
+    /// <summary>
+    /// Run BlueMap with no flags so it writes default configs (bluemap.conf,
+    /// maps/overworld.conf, etc.), then patch the overworld map's world path
+    /// to point at our serverDir. Idempotent -- only writes configs that don't
+    /// exist; existing user edits survive.
+    /// </summary>
+    private void EnsureConfig(string javaPath)
+    {
+        Directory.CreateDirectory(ConfigDir);
+        var bluemapConf = Path.Combine(ConfigDir, "core.conf");
+        var seeded = File.Exists(bluemapConf);
+        if (!seeded)
+        {
+            _log("[bluemap] First run -- generating default configs.");
+            var psi = new ProcessStartInfo
+            {
+                FileName = javaPath,
+                WorkingDirectory = RootDir,
+                UseShellExecute = false,
+                RedirectStandardOutput = true,
+                RedirectStandardError = true,
+                CreateNoWindow = true,
+            };
+            psi.ArgumentList.Add("-jar");
+            psi.ArgumentList.Add(CliJarPath);
+            using var p = Process.Start(psi)!;
+            p.WaitForExit(60_000);
+        }
+
+        // Patch the overworld map config to reference our world dir.
+        var serverDirAbs = Path.GetFullPath(_config.ServerDir);
+        var levelName = ReadLevelName(_config.ServerDir) ?? "world";
+        var worldDir = Path.Combine(serverDirAbs, levelName).Replace('\\', '/');
+
+        var mapsDir = Path.Combine(ConfigDir, "maps");
+        Directory.CreateDirectory(mapsDir);
+        var owConf = Path.Combine(mapsDir, "overworld.conf");
+        if (!File.Exists(owConf) || !File.ReadAllText(owConf).Contains(worldDir))
+        {
+            File.WriteAllText(owConf, $@"# Generated by brass-sigil-server. Edit at your own risk.
+world: ""{worldDir}""
+dimension: ""minecraft:overworld""
+name: ""Brass and Sigil -- Overworld""
+sorting: 0
+sky-color: ""#7dabff""
+ambient-light: 0
+");
+            _log("[bluemap] Wrote map config: maps/overworld.conf");
+        }
+
+        // Tell core.conf to accept that we read its license/disclaimer (otherwise CLI exits with a notice).
+        if (File.Exists(bluemapConf))
+        {
+            var text = File.ReadAllText(bluemapConf);
+            if (!text.Contains("accept-download: true"))
+            {
+                text = text.Replace("accept-download: false", "accept-download: true");
+                if (!text.Contains("accept-download:"))
+                    text += "\naccept-download: true\n";
+                File.WriteAllText(bluemapConf, text);
+                _log("[bluemap] Set accept-download: true in core.conf");
+            }
+        }
+    }
+
+    private static string? ReadLevelName(string serverDir)
+    {
+        var path = Path.Combine(serverDir, "server.properties");
+        if (!File.Exists(path)) return null;
+        foreach (var line in File.ReadAllLines(path))
+        {
+            if (line.StartsWith("level-name=", StringComparison.Ordinal))
+                return line.Substring("level-name=".Length).Trim();
+        }
+        return null;
+    }
+}

server/Services/Broadcaster.cs

@@ -0,0 +1,109 @@
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Pushes player-visible messages and overlays into Minecraft via stdin
+/// commands (/say, /title, /bossbar). The boss-bar countdown is the primary
+/// primitive the updater uses for restart announcements.
+/// </summary>
+public sealed class Broadcaster
+{
+    private readonly ServerProcess _proc;
+    private const string BossBarId = "brass:announce";
+
+    public Broadcaster(ServerProcess proc) => _proc = proc;
+
+    public Task SayAsync(string message, CancellationToken ct = default)
+        => _proc.SendInputAsync($"say {SingleLine(message)}", ct);
+
+    public Task ActionBarAsync(string message, CancellationToken ct = default)
+        => _proc.SendInputAsync($"title @a actionbar {{\"text\":\"{EscapeJson(message)}\"}}", ct);
+
+    /// <summary>
+    /// Re-sends the action bar text once per second so it stays sticky for the
+    /// full duration. Action bar fades after ~2-3 s of inactivity, so the
+    /// re-send is mandatory. Doesn't conflict with boss-bar UI for actual
+    /// boss fights -- preferred over BossBarCountdownAsync for restart warnings.
+    /// </summary>
+    public async Task ActionBarCountdownAsync(
+        string title, int durationSeconds, CancellationToken ct = default)
+    {
+        if (durationSeconds <= 0) return;
+        // Silence /title's "Showing new title for X" chat broadcast for the loop --
+        // otherwise it spams chat once per second per online player. Restored in
+        // the finally block. World save typically isn't quick enough to persist
+        // the off state if we crash mid-flight, but worst case admins can flip
+        // it back manually with /gamerule sendCommandFeedback true.
+        await _proc.SendInputAsync("gamerule sendCommandFeedback false", ct);
+        try
+        {
+            for (int sec = durationSeconds; sec > 0; sec--)
+            {
+                ct.ThrowIfCancellationRequested();
+                var mins = sec / 60;
+                var secs = sec % 60;
+                var label = mins > 0 ? $"{title} -- {mins}m {secs:00}s" : $"{title} -- {secs}s";
+                await _proc.SendInputAsync($"title @a actionbar {{\"text\":\"{EscapeJson(label)}\"}}", ct);
+                try { await Task.Delay(1000, ct); }
+                catch (OperationCanceledException) { throw; }
+            }
+        }
+        finally
+        {
+            // Clear the action bar AND restore feedback. Both best-effort: if MC
+            // is stopping these'll fail and that's fine.
+            try { await _proc.SendInputAsync("title @a actionbar {\"text\":\"\"}"); } catch { }
+            try { await _proc.SendInputAsync("gamerule sendCommandFeedback true"); } catch { }
+        }
+    }
+
+    public Task TitleAsync(string message, CancellationToken ct = default)
+        => _proc.SendInputAsync($"title @a title {{\"text\":\"{EscapeJson(message)}\"}}", ct);
+
+    /// <summary>
+    /// Show a draining boss bar at the top of every player's screen for
+    /// <paramref name="durationSeconds"/>. Updates the bar's name with a
+    /// "title -- Mm Ss" countdown each second. Returns when the bar is removed.
+    /// Honours cancellation: bar is removed cleanly even on cancel.
+    /// </summary>
+    public async Task BossBarCountdownAsync(
+        string title, int durationSeconds, string color = "yellow", CancellationToken ct = default)
+    {
+        if (durationSeconds <= 0) return;
+
+        // Silence /bossbar feedback for the same reason as ActionBarCountdownAsync.
+        await _proc.SendInputAsync("gamerule sendCommandFeedback false", ct);
+        await _proc.SendInputAsync($"bossbar add {BossBarId} {{\"text\":\"{EscapeJson(title)}\"}}", ct);
+        await _proc.SendInputAsync($"bossbar set {BossBarId} color {color}", ct);
+        await _proc.SendInputAsync($"bossbar set {BossBarId} max {durationSeconds}", ct);
+        await _proc.SendInputAsync($"bossbar set {BossBarId} value {durationSeconds}", ct);
+        await _proc.SendInputAsync($"bossbar set {BossBarId} players @a", ct);
+
+        try
+        {
+            for (int sec = durationSeconds; sec > 0; sec--)
+            {
+                ct.ThrowIfCancellationRequested();
+                var mins = sec / 60;
+                var secs = sec % 60;
+                var label = mins > 0 ? $"{title} -- {mins}m {secs:00}s" : $"{title} -- {secs}s";
+                await _proc.SendInputAsync($"bossbar set {BossBarId} name {{\"text\":\"{EscapeJson(label)}\"}}", ct);
+                await _proc.SendInputAsync($"bossbar set {BossBarId} value {sec}", ct);
+                try { await Task.Delay(1000, ct); }
+                catch (OperationCanceledException) { throw; }
+            }
+        }
+        finally
+        {
+            // Always remove the bar -- even on cancel, so a stuck bar isn't left
+            // on every player's screen. Use CancellationToken.None for the cleanup.
+            try { await _proc.SendInputAsync($"bossbar remove {BossBarId}"); } catch { }
+            try { await _proc.SendInputAsync("gamerule sendCommandFeedback true"); } catch { }
+        }
+    }
+
+    private static string EscapeJson(string s) =>
+        s.Replace("\\", "\\\\").Replace("\"", "\\\"").Replace("\n", " ");
+
+    private static string SingleLine(string s) =>
+        s.Replace("\r", " ").Replace("\n", " ").Trim();
+}

server/Services/JavaInstaller.cs

@@ -0,0 +1,156 @@
+using System.Formats.Tar;
+using System.IO.Compression;
+using System.Runtime.InteropServices;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Downloads + extracts Adoptium Temurin JRE 21 to server/java/. Used as a fallback
+/// when system Java is missing or too old. Adoptium's API gives us a stable
+/// platform-keyed download URL without needing API keys or auth.
+/// </summary>
+public sealed class JavaInstaller
+{
+    private static readonly HttpClient _http = new() { Timeout = TimeSpan.FromMinutes(15) };
+
+    public string GetJavaInstallDir(string serverDir) => Path.Combine(serverDir, "java");
+    public string GetJavaInstallDir(string serverDir, int majorVersion) =>
+        Path.Combine(serverDir, "java" + majorVersion);
+
+    /// <summary>If a previous install put a java executable under serverDir/java/, return its path.</summary>
+    public string? FindBundledJava(string serverDir)
+    {
+        var javaDir = GetJavaInstallDir(serverDir);
+        if (!Directory.Exists(javaDir)) return null;
+        var exe = OperatingSystem.IsWindows() ? "java.exe" : "java";
+        return Directory.EnumerateFiles(javaDir, exe, SearchOption.AllDirectories).FirstOrDefault();
+    }
+
+    /// <summary>Find a Java install for a specific major version (e.g. javaXX/jdk-XX*/bin/java).</summary>
+    public string? FindBundledJava(string serverDir, int majorVersion)
+    {
+        var javaDir = GetJavaInstallDir(serverDir, majorVersion);
+        if (!Directory.Exists(javaDir)) return null;
+        var exe = OperatingSystem.IsWindows() ? "java.exe" : "java";
+        return Directory.EnumerateFiles(javaDir, exe, SearchOption.AllDirectories).FirstOrDefault();
+    }
+
+    public Task<string?> InstallJre21Async(string serverDir, IProgress<string>? progress, CancellationToken ct)
+        => InstallJreAsync(21, serverDir, GetJavaInstallDir(serverDir), progress, ct);
+
+    /// <summary>
+    /// Download + extract Adoptium Temurin JRE for a specific major version into
+    /// <paramref name="installDir"/>. Used by BlueMap to get JRE 25 alongside the
+    /// JRE 21 we use for Minecraft.
+    /// </summary>
+    public async Task<string?> InstallJreAsync(int majorVersion, string serverDir, string installDir,
+                                                IProgress<string>? progress, CancellationToken ct)
+    {
+        var javaDir = installDir;
+        Directory.CreateDirectory(javaDir);
+
+        var (url, archiveName, isZip) = PickAdoptiumDownload(majorVersion);
+        if (url is null)
+        {
+            progress?.Report($"[err] No supported Adoptium binary for {RuntimeInformation.OSDescription} {RuntimeInformation.OSArchitecture}.");
+            return null;
+        }
+
+        var archivePath = Path.Combine(javaDir, archiveName!);
+        progress?.Report($"Downloading Adoptium Temurin JRE 21 ({(isZip ? "zip" : "tar.gz")})...");
+
+        try
+        {
+            using (var resp = await _http.GetAsync(url, HttpCompletionOption.ResponseHeadersRead, ct))
+            {
+                resp.EnsureSuccessStatusCode();
+                await using var src = await resp.Content.ReadAsStreamAsync(ct);
+                await using var dst = File.Create(archivePath);
+                await src.CopyToAsync(dst, ct);
+            }
+        }
+        catch (Exception ex)
+        {
+            progress?.Report($"  [err] Download failed: {ex.Message}");
+            return null;
+        }
+
+        progress?.Report($"  Downloaded {new FileInfo(archivePath).Length:N0} bytes");
+        progress?.Report("Extracting...");
+
+        try
+        {
+            if (isZip)
+            {
+                ZipFile.ExtractToDirectory(archivePath, javaDir, overwriteFiles: true);
+            }
+            else
+            {
+                await using var fs = File.OpenRead(archivePath);
+                await using var gzip = new GZipStream(fs, CompressionMode.Decompress);
+                await TarFile.ExtractToDirectoryAsync(gzip, javaDir, overwriteFiles: true, ct);
+            }
+        }
+        catch (Exception ex)
+        {
+            progress?.Report($"  [err] Extract failed: {ex.Message}");
+            return null;
+        }
+
+        try { File.Delete(archivePath); } catch { /* best-effort */ }
+
+        var javaExe = FindBundledJava(serverDir);
+        if (javaExe is null)
+        {
+            progress?.Report("  [err] Extracted, but couldn't locate bin/java in the result.");
+            return null;
+        }
+
+        // On Linux/macOS, make sure java is executable. TarFile preserves mode bits in
+        // most setups, but be defensive.
+        if (!OperatingSystem.IsWindows())
+        {
+            try
+            {
+                File.SetUnixFileMode(javaExe,
+                    UnixFileMode.UserRead | UnixFileMode.UserWrite | UnixFileMode.UserExecute |
+                    UnixFileMode.GroupRead | UnixFileMode.GroupExecute |
+                    UnixFileMode.OtherRead | UnixFileMode.OtherExecute);
+            }
+            catch { }
+        }
+
+        progress?.Report($"Java {majorVersion} ready: {javaExe}");
+        return javaExe;
+    }
+
+    private static (string? Url, string? ArchiveName, bool IsZip) PickAdoptiumDownload(int majorVersion)
+    {
+        // Adoptium API picks the latest GA release matching our os/arch.
+        // Docs: https://api.adoptium.net/q/swagger-ui/
+        var arch = RuntimeInformation.OSArchitecture switch
+        {
+            Architecture.X64   => "x64",
+            Architecture.Arm64 => "aarch64",
+            _ => null
+        };
+        if (arch is null) return (null, null, false);
+
+        if (OperatingSystem.IsWindows())
+        {
+            return ($"https://api.adoptium.net/v3/binary/latest/{majorVersion}/ga/windows/{arch}/jre/hotspot/normal/eclipse",
+                    $"jre{majorVersion}.zip", true);
+        }
+        if (OperatingSystem.IsLinux())
+        {
+            return ($"https://api.adoptium.net/v3/binary/latest/{majorVersion}/ga/linux/{arch}/jre/hotspot/normal/eclipse",
+                    $"jre{majorVersion}.tar.gz", false);
+        }
+        if (OperatingSystem.IsMacOS())
+        {
+            return ($"https://api.adoptium.net/v3/binary/latest/{majorVersion}/ga/mac/{arch}/jre/hotspot/normal/eclipse",
+                    $"jre{majorVersion}.tar.gz", false);
+        }
+        return (null, null, false);
+    }
+}

server/Services/JsonOpts.cs

@@ -0,0 +1,24 @@
+using System.Text.Json;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Project-wide JSON serializer options. Always case-insensitive on read so that
+/// hand-edited config files / API responses don't silently fail to bind a property
+/// because of a casing mismatch (e.g. "Command" vs "command", "JavaPath" vs "javaPath").
+/// Use this everywhere we call JsonSerializer.Deserialize.
+/// </summary>
+public static class JsonOpts
+{
+    public static readonly JsonSerializerOptions CaseInsensitive = new()
+    {
+        PropertyNameCaseInsensitive = true,
+        ReadCommentHandling = JsonCommentHandling.Skip,
+        AllowTrailingCommas = true,
+    };
+
+    public static readonly JsonSerializerOptions Pretty = new()
+    {
+        WriteIndented = true,
+    };
+}

server/Services/ManifestSync.cs

@@ -0,0 +1,199 @@
+using System.Net.Http.Json;
+using System.Security.Cryptography;
+using System.Text.Json;
+using BrassAndSigil.Server.Models;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Server-side mod sync. Downloads only mods that the server needs:
+/// queries Modrinth's project metadata for each mod's `server_side` field
+/// and skips anything marked "unsupported" (Iris, Sodium, JEI, etc).
+/// CurseForge mods can't be auto-classified without an API key, so they
+/// are downloaded as-is and the server admin can manually delete unwanted ones.
+/// </summary>
+public sealed class ManifestSync
+{
+    private static readonly HttpClient _http = new() { Timeout = TimeSpan.FromMinutes(5) };
+    private const string PackVersionFile = "pack-version.json";
+    private const string ServerManifestCache = "server-pack.cache.json";
+
+    public sealed record SyncResult(int Downloaded, int Removed, int Skipped, string PackVersion);
+
+    public async Task<Manifest> FetchManifestAsync(string url, CancellationToken ct = default)
+    {
+        var json = await _http.GetStringAsync(url, ct);
+        var manifest = JsonSerializer.Deserialize<Manifest>(json, JsonOpts.CaseInsensitive)
+            ?? throw new InvalidOperationException("Manifest is empty.");
+        manifest.Files ??= new();
+        return manifest;
+    }
+
+    public async Task<SyncResult> SyncAsync(
+        string manifestUrl, string serverDir, IProgress<string>? progress = null, CancellationToken ct = default)
+    {
+        progress?.Report("Fetching manifest...");
+        var manifest = await FetchManifestAsync(manifestUrl, ct);
+
+        progress?.Report($"Pack: {manifest.Name} v{manifest.Version}");
+        Directory.CreateDirectory(serverDir);
+
+        // Resolve which mods are server-side.
+        var skipSlugs = await ResolveServerSideSkipListAsync(manifest, ct);
+
+        // Build the filtered list of files to keep on the server.
+        var keepFiles = manifest.Files
+            .Where(f => !ShouldSkipFile(f.Path, skipSlugs))
+            .ToList();
+        var skippedCount = manifest.Files.Count - keepFiles.Count;
+
+        // Prune managed files that aren't in the keep set.
+        var wantedPaths = new HashSet<string>(
+            keepFiles.Select(f => f.Path.Replace('\\', '/')),
+            StringComparer.OrdinalIgnoreCase);
+        var toRemove = ListManagedFiles(serverDir).Where(p => !wantedPaths.Contains(p)).ToList();
+        foreach (var rel in toRemove)
+        {
+            var full = Path.Combine(serverDir, rel);
+            try { File.Delete(full); progress?.Report($"  Removed: {rel}"); }
+            catch (Exception ex) { progress?.Report($"  Could not remove {rel}: {ex.Message}"); }
+        }
+
+        // Download missing or hash-mismatched files.
+        var toDownload = new List<ManifestFile>();
+        foreach (var file in keepFiles)
+        {
+            ct.ThrowIfCancellationRequested();
+            var dest = Path.Combine(serverDir, file.Path);
+            if (!File.Exists(dest)) { toDownload.Add(file); continue; }
+            if (!string.IsNullOrEmpty(file.Sha1))
+            {
+                var actual = await ComputeSha1Async(dest, ct);
+                if (!string.Equals(actual, file.Sha1, StringComparison.OrdinalIgnoreCase))
+                    toDownload.Add(file);
+            }
+        }
+
+        progress?.Report(toDownload.Count == 0 ? "Already up-to-date." : $"Downloading {toDownload.Count} files...");
+        for (int i = 0; i < toDownload.Count; i++)
+        {
+            var file = toDownload[i];
+            progress?.Report($"  [{i + 1}/{toDownload.Count}] {file.Path}");
+            await DownloadFileAsync(file.Url, Path.Combine(serverDir, file.Path), file.Sha1, ct);
+        }
+
+        // Write pack-version.json marker.
+        var record = new
+        {
+            name = manifest.Name,
+            version = manifest.Version,
+            syncedAt = DateTime.UtcNow.ToString("o"),
+            includedFiles = keepFiles.Count,
+            skippedFiles = skippedCount
+        };
+        await File.WriteAllTextAsync(
+            Path.Combine(serverDir, PackVersionFile),
+            JsonSerializer.Serialize(record, new JsonSerializerOptions { WriteIndented = true }),
+            ct);
+
+        return new SyncResult(toDownload.Count, toRemove.Count, skippedCount, manifest.Version ?? "?");
+    }
+
+    private static bool ShouldSkipFile(string filePath, HashSet<string> skipSlugs)
+    {
+        if (skipSlugs.Count == 0) return false;
+        var name = Path.GetFileNameWithoutExtension(filePath).ToLowerInvariant();
+        // Match if any skip slug appears at the start of the filename (slug-version.jar)
+        return skipSlugs.Any(slug => name.StartsWith(slug + "-", StringComparison.OrdinalIgnoreCase)
+                                  || name.Equals(slug, StringComparison.OrdinalIgnoreCase));
+    }
+
+    /// <summary>Walk the manifest's mod URLs; for Modrinth ones, look up server_side; build a skip set.</summary>
+    private async Task<HashSet<string>> ResolveServerSideSkipListAsync(Manifest manifest, CancellationToken ct)
+    {
+        var skip = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        var modrinthIds = new HashSet<string>();
+
+        foreach (var file in manifest.Files)
+        {
+            if (!file.Path.StartsWith("mods/", StringComparison.OrdinalIgnoreCase)) continue;
+            // Modrinth URL pattern: https://cdn.modrinth.com/data/{projectId}/versions/{versionId}/...
+            var url = file.Url;
+            const string prefix = "cdn.modrinth.com/data/";
+            var idx = url.IndexOf(prefix, StringComparison.OrdinalIgnoreCase);
+            if (idx < 0) continue;
+            var rest = url.Substring(idx + prefix.Length);
+            var slash = rest.IndexOf('/');
+            if (slash < 0) continue;
+            modrinthIds.Add(rest.Substring(0, slash));
+        }
+
+        foreach (var pid in modrinthIds)
+        {
+            ct.ThrowIfCancellationRequested();
+            try
+            {
+                var info = await _http.GetFromJsonAsync<JsonElement>(
+                    $"https://api.modrinth.com/v2/project/{pid}", ct);
+                var slug = info.TryGetProperty("slug", out var s) ? s.GetString() : null;
+                var serverSide = info.TryGetProperty("server_side", out var ss) ? ss.GetString() : null;
+                if (!string.IsNullOrEmpty(slug) && string.Equals(serverSide, "unsupported", StringComparison.OrdinalIgnoreCase))
+                {
+                    skip.Add(slug);
+                }
+            }
+            catch
+            {
+                // Best-effort: if we can't classify, keep the mod (safer to ship extra than missing)
+            }
+        }
+
+        return skip;
+    }
+
+    private static List<string> ListManagedFiles(string serverDir)
+    {
+        var roots = new[] { "mods", "config", "resourcepacks", "kubejs", "defaultconfigs" };
+        var result = new List<string>();
+        foreach (var root in roots)
+        {
+            var rootDir = Path.Combine(serverDir, root);
+            if (!Directory.Exists(rootDir)) continue;
+            foreach (var f in Directory.EnumerateFiles(rootDir, "*", SearchOption.AllDirectories))
+                result.Add(Path.GetRelativePath(serverDir, f).Replace('\\', '/'));
+        }
+        return result;
+    }
+
+    private static async Task DownloadFileAsync(string url, string destPath, string? expectedSha1, CancellationToken ct)
+    {
+        Directory.CreateDirectory(Path.GetDirectoryName(destPath)!);
+        var tmp = destPath + ".part";
+        using (var resp = await _http.GetAsync(url, HttpCompletionOption.ResponseHeadersRead, ct))
+        {
+            resp.EnsureSuccessStatusCode();
+            await using var src = await resp.Content.ReadAsStreamAsync(ct);
+            await using var dst = File.Create(tmp);
+            await src.CopyToAsync(dst, ct);
+        }
+        if (!string.IsNullOrEmpty(expectedSha1))
+        {
+            var actual = await ComputeSha1Async(tmp, ct);
+            if (!string.Equals(actual, expectedSha1, StringComparison.OrdinalIgnoreCase))
+            {
+                File.Delete(tmp);
+                throw new InvalidOperationException($"Hash mismatch for {Path.GetFileName(destPath)}");
+            }
+        }
+        if (File.Exists(destPath)) File.Delete(destPath);
+        File.Move(tmp, destPath);
+    }
+
+    private static async Task<string> ComputeSha1Async(string path, CancellationToken ct)
+    {
+        using var sha = SHA1.Create();
+        await using var stream = File.OpenRead(path);
+        var bytes = await sha.ComputeHashAsync(stream, ct);
+        return Convert.ToHexString(bytes).ToLowerInvariant();
+    }
+}

server/Services/NeoForgeInstaller.cs

@@ -0,0 +1,112 @@
+using System.Diagnostics;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Downloads NeoForge's official server installer JAR and runs it with --installServer
+/// to produce run.sh/run.bat + the server library tree. Handles Java invocation and
+/// streams installer output via a progress callback.
+/// </summary>
+public sealed class NeoForgeInstaller
+{
+    private static readonly HttpClient _http = new() { Timeout = TimeSpan.FromMinutes(10) };
+
+    public bool IsAlreadyInstalled(string serverDir)
+    {
+        return File.Exists(Path.Combine(serverDir, OperatingSystem.IsWindows() ? "run.bat" : "run.sh"));
+    }
+
+    public async Task<bool> InstallAsync(string version, string serverDir, string javaPath,
+                                         IProgress<string>? progress, CancellationToken ct)
+    {
+        Directory.CreateDirectory(serverDir);
+
+        // 1. Download installer
+        var installerName = $"neoforge-{version}-installer.jar";
+        var installerPath = Path.Combine(serverDir, installerName);
+        var url = $"https://maven.neoforged.net/releases/net/neoforged/neoforge/{version}/{installerName}";
+
+        if (!File.Exists(installerPath))
+        {
+            progress?.Report($"Downloading NeoForge {version} installer...");
+            var bytes = await _http.GetByteArrayAsync(url, ct);
+            await File.WriteAllBytesAsync(installerPath, bytes, ct);
+            progress?.Report($"  Saved {bytes.Length:N0} bytes to {installerName}");
+        }
+        else
+        {
+            progress?.Report($"NeoForge installer already present, skipping download.");
+        }
+
+        // 2. Run installer
+        progress?.Report("Running NeoForge installer (java -jar ... --installServer)...");
+        var psi = new ProcessStartInfo
+        {
+            FileName = javaPath,
+            WorkingDirectory = serverDir,
+            UseShellExecute = false,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            CreateNoWindow = true,
+        };
+        psi.ArgumentList.Add("-jar");
+        psi.ArgumentList.Add(installerName);
+        psi.ArgumentList.Add("--installServer");
+
+        Process? proc;
+        try
+        {
+            proc = Process.Start(psi);
+        }
+        catch (Exception ex)
+        {
+            progress?.Report($"  [error] Could not start java: {ex.Message}");
+            return false;
+        }
+        if (proc is null)
+        {
+            progress?.Report("  [error] Failed to start java.");
+            return false;
+        }
+
+        var stdoutTask = StreamLines(proc.StandardOutput, line => progress?.Report($"  {line}"), ct);
+        var stderrTask = StreamLines(proc.StandardError, line => progress?.Report($"  [err] {line}"), ct);
+
+        await proc.WaitForExitAsync(ct);
+        await Task.WhenAll(stdoutTask, stderrTask);
+
+        if (proc.ExitCode != 0)
+        {
+            progress?.Report($"  [error] NeoForge installer exited with code {proc.ExitCode}");
+            return false;
+        }
+
+        // 3. Verify run script exists
+        if (!IsAlreadyInstalled(serverDir))
+        {
+            progress?.Report("  [error] NeoForge installer ran but run.sh/run.bat is missing.");
+            return false;
+        }
+
+        progress?.Report($"NeoForge {version} installed.");
+
+        // 4. Clean up the installer JAR (large, no longer needed)
+        try { File.Delete(installerPath); } catch { /* best-effort */ }
+
+        return true;
+    }
+
+    private static async Task StreamLines(StreamReader reader, Action<string> onLine, CancellationToken ct)
+    {
+        try
+        {
+            while (!reader.EndOfStream)
+            {
+                var line = await reader.ReadLineAsync(ct);
+                if (line is null) break;
+                onLine(line);
+            }
+        }
+        catch { }
+    }
+}

server/Services/RconClient.cs

@@ -0,0 +1,93 @@
+using System.Buffers.Binary;
+using System.Net.Sockets;
+using System.Text;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Minimal Minecraft RCON client (Source RCON protocol).
+/// Used for sending console commands and reading "list" output for player counts.
+/// </summary>
+public sealed class RconClient : IDisposable
+{
+    private const int SERVERDATA_AUTH = 3;
+    private const int SERVERDATA_EXECCOMMAND = 2;
+    private const int SERVERDATA_RESPONSE_VALUE = 0;
+
+    private TcpClient? _tcp;
+    private NetworkStream? _stream;
+    private int _nextRequestId = 1;
+
+    public bool Connected => _tcp?.Connected ?? false;
+
+    public async Task ConnectAsync(string host, int port, string password, CancellationToken ct = default)
+    {
+        _tcp = new TcpClient();
+        await _tcp.ConnectAsync(host, port, ct);
+        _stream = _tcp.GetStream();
+
+        var authId = NextId();
+        await SendPacketAsync(authId, SERVERDATA_AUTH, password, ct);
+
+        // Read auth response. Server sends an empty response value first, then the auth result.
+        var (id1, _, _) = await ReadPacketAsync(ct);
+        if (id1 == -1) throw new InvalidOperationException("RCON auth failed (bad password)");
+        // Auth ok if id matches what we sent
+    }
+
+    public async Task<string> SendCommandAsync(string command, CancellationToken ct = default)
+    {
+        if (_stream == null) throw new InvalidOperationException("Not connected");
+        var id = NextId();
+        await SendPacketAsync(id, SERVERDATA_EXECCOMMAND, command, ct);
+        var (_, _, body) = await ReadPacketAsync(ct);
+        return body;
+    }
+
+    private int NextId() => Interlocked.Increment(ref _nextRequestId);
+
+    private async Task SendPacketAsync(int id, int type, string body, CancellationToken ct)
+    {
+        var bodyBytes = Encoding.UTF8.GetBytes(body);
+        var packetSize = 4 + 4 + bodyBytes.Length + 2; // id + type + body + 2 null bytes
+        var buffer = new byte[4 + packetSize];
+        BinaryPrimitives.WriteInt32LittleEndian(buffer.AsSpan(0, 4), packetSize);
+        BinaryPrimitives.WriteInt32LittleEndian(buffer.AsSpan(4, 4), id);
+        BinaryPrimitives.WriteInt32LittleEndian(buffer.AsSpan(8, 4), type);
+        bodyBytes.CopyTo(buffer.AsSpan(12));
+        // last two bytes already 0 by default
+        await _stream!.WriteAsync(buffer, ct);
+    }
+
+    private async Task<(int Id, int Type, string Body)> ReadPacketAsync(CancellationToken ct)
+    {
+        var sizeBuf = new byte[4];
+        await ReadExactAsync(sizeBuf, ct);
+        var size = BinaryPrimitives.ReadInt32LittleEndian(sizeBuf);
+        if (size < 10 || size > 1024 * 1024) throw new InvalidOperationException($"Bad RCON packet size {size}");
+
+        var pkt = new byte[size];
+        await ReadExactAsync(pkt, ct);
+        var id = BinaryPrimitives.ReadInt32LittleEndian(pkt.AsSpan(0, 4));
+        var type = BinaryPrimitives.ReadInt32LittleEndian(pkt.AsSpan(4, 4));
+        var body = Encoding.UTF8.GetString(pkt, 8, size - 10); // strip 2 trailing nulls
+        return (id, type, body);
+    }
+
+    private async Task ReadExactAsync(byte[] buffer, CancellationToken ct)
+    {
+        var read = 0;
+        while (read < buffer.Length)
+        {
+            var n = await _stream!.ReadAsync(buffer.AsMemory(read), ct);
+            if (n == 0) throw new EndOfStreamException();
+            read += n;
+        }
+    }
+
+    public void Dispose()
+    {
+        _stream?.Dispose();
+        _tcp?.Dispose();
+    }
+}

server/Services/RconManager.cs

@@ -0,0 +1,68 @@
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Thin reconnecting wrapper around <see cref="RconClient"/>. The original
+/// single-connection-with-no-retry pattern caches a dead client whenever the
+/// initial connect happens before MC has opened the RCON port (which is normal --
+/// boot takes ~30 s). This manager lazily connects on first use, retries on
+/// failure, and drops the client when a send throws so the next call reconnects.
+/// </summary>
+public sealed class RconManager : IDisposable
+{
+    private readonly string _host;
+    private readonly int _port;
+    private readonly string _password;
+    private readonly SemaphoreSlim _lock = new(1, 1);
+    private RconClient? _client;
+
+    public RconManager(string host, int port, string password)
+    {
+        _host = host;
+        _port = port;
+        _password = password;
+    }
+
+    public async Task<string> SendCommandAsync(string command, CancellationToken ct = default)
+    {
+        var client = await EnsureConnectedAsync(ct);
+        try
+        {
+            return await client.SendCommandAsync(command, ct);
+        }
+        catch
+        {
+            await DropAsync();
+            throw;
+        }
+    }
+
+    private async Task<RconClient> EnsureConnectedAsync(CancellationToken ct)
+    {
+        await _lock.WaitAsync(ct);
+        try
+        {
+            if (_client is { Connected: true }) return _client;
+            _client?.Dispose();
+            _client = new RconClient();
+            await _client.ConnectAsync(_host, _port, _password, ct);
+            return _client;
+        }
+        finally
+        {
+            _lock.Release();
+        }
+    }
+
+    private async Task DropAsync()
+    {
+        await _lock.WaitAsync();
+        try { _client?.Dispose(); _client = null; }
+        finally { _lock.Release(); }
+    }
+
+    public void Dispose()
+    {
+        _client?.Dispose();
+        _lock.Dispose();
+    }
+}

server/Services/ServerProcess.cs

@@ -0,0 +1,405 @@
+using System.Collections.Concurrent;
+using System.Diagnostics;
+using BrassAndSigil.Server.Models;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Manages the Minecraft Java subprocess: spawns it with the right JVM args,
+/// captures stdout/stderr into a ring buffer (so the web UI can show recent
+/// logs), broadcasts new lines via an event, handles graceful shutdown.
+/// </summary>
+public sealed class ServerProcess : IDisposable
+{
+    private readonly ServerConfig _config;
+    private Process? _process;
+    private readonly ConcurrentQueue<LogLine> _logRing = new();
+    private const int LogRingSize = 2000;
+
+    // Process-tree containment: on Windows, the Job Object kills our subprocess
+    // automatically when our own process dies -- regardless of how we died.
+    // Created lazily on first Start() on Windows; destroyed in Dispose.
+    private static WindowsJobObject? _jobObject;
+
+    public event Action<LogLine>? OnLogLine;
+    public event Action<int>? Exited;
+
+    public bool IsRunning => _process is { HasExited: false };
+    public DateTime? StartedAt { get; private set; }
+    public int? Pid => _process?.Id;
+
+    // Memory + CPU sampling. CpuMetrics is a moving average across calls -- the
+    // first call after start returns null because we need two samples for a delta.
+    // We track the Java *descendant* of our shell, not the shell itself, because
+    // run.sh / run.bat is ~2 MB and useless for stats.
+    private TimeSpan _lastCpuTime;
+    private DateTime _lastCpuSampleAt;
+    private int _lastTrackedPid;
+    private Process? _trackedJava;
+    private readonly object _statsLock = new();
+    private readonly Queue<double> _cpuSamples = new();
+    private const int CpuSampleWindow = 20; // ~60 s rolling window @ 3 s polling
+
+    /// <summary>
+    /// Returns the Java JVM descendant if found, otherwise falls back to the
+    /// directly-spawned shell process. Cached and re-resolved when the cached
+    /// pid exits (e.g., MC restart).
+    /// </summary>
+    private Process? TrackedProcess
+    {
+        get
+        {
+            if (_process is null || _process.HasExited) return null;
+            if (_trackedJava is { HasExited: false }) return _trackedJava;
+            // Try to find a 'java' descendant of our shell. If not found yet (still
+            // booting), fall back to the shell -- first stats will read tiny, then
+            // reset on next call once Java is up.
+            var found = FindJavaDescendant(_process.Id);
+            _trackedJava = found;
+            return found ?? _process;
+        }
+    }
+
+    public long? MemoryBytes
+    {
+        get
+        {
+            var p = TrackedProcess;
+            if (p is null || p.HasExited) return null;
+            try { p.Refresh(); return p.WorkingSet64; }
+            catch { return null; }
+        }
+    }
+
+    /// <summary>
+    /// System-wide CPU percentage (0-100) plus rolling-window peak and average.
+    /// Each call samples once and contributes to a 20-entry history (~60 s at 3 s
+    /// polling). First call after start returns null (need two samples for a delta).
+    /// </summary>
+    public (double Current, double Max, double Avg)? CpuMetrics
+    {
+        get
+        {
+            var p = TrackedProcess;
+            if (p is null || p.HasExited) return null;
+            lock (_statsLock)
+            {
+                try
+                {
+                    p.Refresh();
+                    var now = DateTime.UtcNow;
+                    var cpuNow = p.TotalProcessorTime;
+                    if (_lastTrackedPid != p.Id || _lastCpuSampleAt == default)
+                    {
+                        _lastTrackedPid  = p.Id;
+                        _lastCpuTime    = cpuNow;
+                        _lastCpuSampleAt = now;
+                        _cpuSamples.Clear();
+                        return null;
+                    }
+                    var elapsedReal = (now - _lastCpuSampleAt).TotalMilliseconds;
+                    var elapsedCpu  = (cpuNow - _lastCpuTime).TotalMilliseconds;
+                    _lastCpuTime = cpuNow;
+                    _lastCpuSampleAt = now;
+                    if (elapsedReal <= 0) return (0, 0, 0);
+
+                    // System-wide: divide by core count so the value is bounded 0-100
+                    // and intuitive ("42% of total CPU capacity"). The user found the
+                    // top-style 0-N*100 range confusing for a fleet view.
+                    var perCore    = elapsedCpu / elapsedReal * 100.0;
+                    var systemWide = Math.Min(100.0, perCore / Environment.ProcessorCount);
+
+                    _cpuSamples.Enqueue(systemWide);
+                    while (_cpuSamples.Count > CpuSampleWindow) _cpuSamples.Dequeue();
+
+                    return (systemWide, _cpuSamples.Max(), _cpuSamples.Average());
+                }
+                catch { return null; }
+            }
+        }
+    }
+
+    /// <summary>
+    /// BFS the process tree starting from <paramref name="rootPid"/> looking for
+    /// a process named like "java". Linux: read /proc/PID/task/PID/children.
+    /// Windows: enumerate parents via Process objects (no extra deps).
+    /// </summary>
+    private static Process? FindJavaDescendant(int rootPid)
+    {
+        try
+        {
+            if (OperatingSystem.IsLinux())
+            {
+                return FindJavaDescendantLinux(rootPid);
+            }
+            if (OperatingSystem.IsWindows())
+            {
+                return FindJavaDescendantWindows(rootPid);
+            }
+        }
+        catch { }
+        return null;
+    }
+
+    private static Process? FindJavaDescendantLinux(int rootPid)
+    {
+        var visited = new HashSet<int>();
+        var queue = new Queue<int>();
+        queue.Enqueue(rootPid);
+        while (queue.Count > 0)
+        {
+            var pid = queue.Dequeue();
+            if (!visited.Add(pid)) continue;
+            var childrenPath = $"/proc/{pid}/task/{pid}/children";
+            if (!File.Exists(childrenPath)) continue;
+            string raw;
+            try { raw = File.ReadAllText(childrenPath); } catch { continue; }
+            foreach (var token in raw.Split(' ', StringSplitOptions.RemoveEmptyEntries))
+            {
+                if (!int.TryParse(token, out var cpid)) continue;
+                Process? p = null;
+                try { p = Process.GetProcessById(cpid); } catch { continue; }
+                if (p.ProcessName.Equals("java", StringComparison.OrdinalIgnoreCase))
+                    return p;
+                queue.Enqueue(cpid);
+            }
+        }
+        return null;
+    }
+
+    private static Process? FindJavaDescendantWindows(int rootPid)
+    {
+        // Build a parent->children map by reading every running process's parent
+        // PID once, then BFS. Slower than Linux's /proc but works without WMI.
+        var allProcs = Process.GetProcesses();
+        var byParent = new Dictionary<int, List<Process>>();
+        foreach (var p in allProcs)
+        {
+            int parent;
+            try { parent = GetParentPidWindows(p); } catch { continue; }
+            if (parent == 0) continue;
+            if (!byParent.TryGetValue(parent, out var list)) byParent[parent] = list = new List<Process>();
+            list.Add(p);
+        }
+        var visited = new HashSet<int>();
+        var queue = new Queue<int>();
+        queue.Enqueue(rootPid);
+        while (queue.Count > 0)
+        {
+            var pid = queue.Dequeue();
+            if (!visited.Add(pid)) continue;
+            if (!byParent.TryGetValue(pid, out var children)) continue;
+            foreach (var c in children)
+            {
+                if (c.ProcessName.Equals("java", StringComparison.OrdinalIgnoreCase))
+                    return c;
+                queue.Enqueue(c.Id);
+            }
+        }
+        return null;
+    }
+
+    [System.Runtime.InteropServices.DllImport("ntdll.dll")]
+    private static extern int NtQueryInformationProcess(
+        IntPtr processHandle, int processInformationClass,
+        ref ProcessBasicInformation processInformation, int processInformationLength, out int returnLength);
+
+    [System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    private struct ProcessBasicInformation
+    {
+        public IntPtr Reserved1;
+        public IntPtr PebBaseAddress;
+        public IntPtr Reserved2_0;
+        public IntPtr Reserved2_1;
+        public IntPtr UniqueProcessId;
+        public IntPtr InheritedFromUniqueProcessId; // <-- parent PID
+    }
+
+    private static int GetParentPidWindows(Process p)
+    {
+        var info = new ProcessBasicInformation();
+        int rc = NtQueryInformationProcess(p.Handle, 0, ref info,
+            System.Runtime.InteropServices.Marshal.SizeOf<ProcessBasicInformation>(), out _);
+        return rc != 0 ? 0 : info.InheritedFromUniqueProcessId.ToInt32();
+    }
+
+    public ServerProcess(ServerConfig config) => _config = config;
+
+    public bool Start()
+    {
+        if (IsRunning) return false;
+
+        // Reset cached Java descendant + CPU sampling baseline so the next call
+        // re-resolves once the new run.sh -> java tree is up.
+        _trackedJava = null;
+        _lastTrackedPid = 0;
+        _lastCpuSampleAt = default;
+
+        // The mod loader's start script lives next to the server jar. NeoForge produces
+        // run.bat / run.sh from its installer; CmlLib's NeoForgeInstaller doesn't run on
+        // the server side, so we build the equivalent JVM command ourselves.
+        var startScript = ResolveStartCommand(out var argList);
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = startScript,
+            WorkingDirectory = Path.GetFullPath(_config.ServerDir),
+            UseShellExecute = false,
+            RedirectStandardInput = true,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            CreateNoWindow = true,
+        };
+        foreach (var a in argList) startInfo.ArgumentList.Add(a);
+
+        // CRITICAL: NeoForge's run.bat / run.sh just calls plain `java`, which resolves to
+        // whatever's on PATH. If we configured a specific Java (or auto-downloaded one),
+        // prepend its bin dir + set JAVA_HOME so the script picks up the right JVM
+        // instead of an older system Java.
+        ApplyJavaEnvironment(startInfo);
+
+        _process = new Process { StartInfo = startInfo, EnableRaisingEvents = true };
+        _process.OutputDataReceived += (_, e) => OnLine(e.Data, isError: false);
+        _process.ErrorDataReceived  += (_, e) => OnLine(e.Data, isError: true);
+        _process.Exited += (_, _) =>
+        {
+            var code = _process?.ExitCode ?? -1;
+            OnLine($"=== Server exited (code {code}) ===", isError: false);
+            Exited?.Invoke(code);
+        };
+
+        _process.Start();
+
+        // Bind the Java subprocess to a Job Object on Windows so it gets killed
+        // automatically if we exit ungracefully (X-button, Task Manager, etc.).
+        if (OperatingSystem.IsWindows())
+        {
+            try
+            {
+                _jobObject ??= new WindowsJobObject();
+                _jobObject.AssignProcess(_process);
+            }
+            catch (Exception ex)
+            {
+                // Non-fatal -- we still try to clean up via Process.Kill in Dispose.
+                OnLine($"[brass-sigil-server] Couldn't attach Job Object: {ex.Message}", isError: true);
+            }
+        }
+
+        _process.BeginOutputReadLine();
+        _process.BeginErrorReadLine();
+        StartedAt = DateTime.UtcNow;
+        return true;
+    }
+
+    private string ResolveStartCommand(out List<string> args)
+    {
+        args = new List<string>();
+        var dir = Path.GetFullPath(_config.ServerDir);
+
+        // Prefer NeoForge's generated run.sh / run.bat -- they include the right module-path JVM args.
+        var runShell = OperatingSystem.IsWindows() ? "run.bat" : "run.sh";
+        var runScript = Path.Combine(dir, runShell);
+        if (File.Exists(runScript))
+        {
+            // Make sure the user_jvm_args.txt has the memory we want
+            EnsureUserJvmArgs(dir);
+            // Suppress the Swing server-GUI window -- we use the web panel instead.
+            // NeoForge's run.bat / run.sh forwards extra args to Minecraft.
+            args.Add("nogui");
+            return runScript;
+        }
+
+        // Fallback: invoke java directly on the server jar. This won't work for NeoForge
+        // (it requires the loader's run script), but it works for vanilla and Forge legacy.
+        args.Add($"-Xms{_config.MemoryMB}M");
+        args.Add($"-Xmx{_config.MemoryMB}M");
+        args.Add("-jar");
+        args.Add("server.jar");
+        args.Add("nogui");
+        return _config.JavaPath;
+    }
+
+    private void ApplyJavaEnvironment(ProcessStartInfo psi)
+    {
+        // Only meaningful when we have an absolute path to a specific java binary
+        // (i.e., not just "java" on PATH).
+        if (string.IsNullOrEmpty(_config.JavaPath)) return;
+        if (!Path.IsPathRooted(_config.JavaPath)) return;
+        if (!File.Exists(_config.JavaPath)) return;
+
+        var javaBinDir = Path.GetDirectoryName(_config.JavaPath);
+        if (string.IsNullOrEmpty(javaBinDir)) return;
+        var javaHome = Path.GetDirectoryName(javaBinDir); // parent of bin/
+
+        var sep = OperatingSystem.IsWindows() ? ";" : ":";
+        var existingPath = Environment.GetEnvironmentVariable("PATH") ?? "";
+        psi.Environment["PATH"] = $"{javaBinDir}{sep}{existingPath}";
+        if (!string.IsNullOrEmpty(javaHome))
+        {
+            psi.Environment["JAVA_HOME"] = javaHome;
+        }
+    }
+
+    private void EnsureUserJvmArgs(string dir)
+    {
+        // NeoForge's run.bat / run.sh reads this file for JVM-level args.
+        // Generational ZGC: concurrent low-pause GC, recommended by Distant Horizons
+        // and significantly better than G1 for heavily-modded MC. Requires Java 21+.
+        var path = Path.Combine(dir, "user_jvm_args.txt");
+        var content =
+            $"-Xms{_config.MemoryMB}M\n" +
+            $"-Xmx{_config.MemoryMB}M\n" +
+            "-XX:+UseZGC\n" +
+            "-XX:+ZGenerational\n";
+        try { File.WriteAllText(path, content); } catch { /* best-effort */ }
+    }
+
+    private void OnLine(string? data, bool isError)
+    {
+        if (string.IsNullOrEmpty(data)) return;
+        var line = new LogLine(DateTimeOffset.UtcNow, isError, data);
+        _logRing.Enqueue(line);
+        while (_logRing.Count > LogRingSize) _logRing.TryDequeue(out _);
+        OnLogLine?.Invoke(line);
+    }
+
+    public IReadOnlyList<LogLine> RecentLogs() => _logRing.ToArray();
+
+    public async Task SendInputAsync(string command, CancellationToken ct = default)
+    {
+        if (_process is null || _process.HasExited) return;
+        await _process.StandardInput.WriteLineAsync(command.AsMemory(), ct);
+        await _process.StandardInput.FlushAsync(ct);
+    }
+
+    public async Task<bool> StopAsync(TimeSpan? graceful = null, CancellationToken ct = default)
+    {
+        if (!IsRunning) return false;
+        graceful ??= TimeSpan.FromSeconds(30);
+        try
+        {
+            await SendInputAsync("stop", ct);
+            using var cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
+            cts.CancelAfter(graceful.Value);
+            try { await _process!.WaitForExitAsync(cts.Token); return true; }
+            catch (OperationCanceledException)
+            {
+                _process?.Kill(entireProcessTree: true);
+                return false;
+            }
+        }
+        catch
+        {
+            try { _process?.Kill(entireProcessTree: true); } catch { }
+            return false;
+        }
+    }
+
+    public void Dispose()
+    {
+        try { _process?.Kill(entireProcessTree: true); } catch { }
+        _process?.Dispose();
+    }
+
+    public sealed record LogLine(DateTimeOffset At, bool IsError, string Text);
+}

server/Services/ServerPropertiesService.cs

@@ -0,0 +1,149 @@
+using BrassAndSigil.Server.Models;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Reads and writes Minecraft's <c>server.properties</c>. Editable keys are
+/// gated by an allowlist so a compromised panel can't flip security-critical
+/// fields like <c>online-mode</c> arbitrarily -- only common gameplay knobs.
+/// Preserves comments and key order on write; appends new keys at the end.
+/// </summary>
+public sealed class ServerPropertiesService
+{
+    private readonly ServerConfig _config;
+
+    public ServerPropertiesService(ServerConfig config) => _config = config;
+
+    /// <summary>
+    /// Keys that may be modified via /api/server/settings. Anything outside this
+    /// set is silently dropped from the update payload -- admin must SSH for those.
+    /// </summary>
+    public static readonly IReadOnlySet<string> EditableKeys = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
+    {
+        "motd",
+        "difficulty",
+        "gamemode",
+        "view-distance",
+        "simulation-distance",
+        "max-players",
+        "pvp",
+        "hardcore",
+        "white-list",
+        "enforce-whitelist",
+        "allow-flight",
+        "enable-command-block",
+        "spawn-protection",
+    };
+
+    public string PropertiesPath => Path.Combine(Path.GetFullPath(_config.ServerDir), "server.properties");
+
+    public Dictionary<string, string> ReadAll()
+    {
+        var dict = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        if (!File.Exists(PropertiesPath)) return dict;
+        foreach (var raw in File.ReadAllLines(PropertiesPath))
+        {
+            var line = raw.TrimStart();
+            if (line.Length == 0 || line[0] == '#' || line[0] == '!') continue;
+            var idx = line.IndexOf('=');
+            if (idx < 0) continue;
+            dict[line.Substring(0, idx).Trim()] = line.Substring(idx + 1);
+        }
+        return dict;
+    }
+
+    /// <summary>Returns just the editable subset, with values left as raw strings.</summary>
+    public Dictionary<string, string> ReadEditable()
+    {
+        var all = ReadAll();
+        var result = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        foreach (var key in EditableKeys)
+        {
+            if (all.TryGetValue(key, out var v)) result[key] = v;
+        }
+        return result;
+    }
+
+    /// <summary>
+    /// Read the current <c>level-seed</c> value, or null if absent / empty.
+    /// </summary>
+    public string? GetLevelSeed()
+    {
+        if (!File.Exists(PropertiesPath)) return null;
+        foreach (var raw in File.ReadAllLines(PropertiesPath))
+        {
+            var line = raw.TrimStart();
+            if (!line.StartsWith("level-seed=", StringComparison.Ordinal)) continue;
+            var v = line.Substring("level-seed=".Length).Trim();
+            return string.IsNullOrEmpty(v) ? null : v;
+        }
+        return null;
+    }
+
+    /// <summary>
+    /// Direct write of <c>level-seed</c>. Bypasses <see cref="EditableKeys"/>
+    /// because the seed is set as part of the wipe flow (with confirmation),
+    /// not by general settings UI -- exposing it through the regular Update()
+    /// path would let it be flipped from any settings save. Empty string
+    /// clears the field, which makes Minecraft pick a random seed on next
+    /// world generation.
+    /// </summary>
+    public void SetLevelSeed(string seed)
+    {
+        var lines = File.Exists(PropertiesPath)
+            ? File.ReadAllLines(PropertiesPath).ToList()
+            : new List<string>();
+        var done = false;
+        for (int i = 0; i < lines.Count; i++)
+        {
+            var trimmed = lines[i].TrimStart();
+            if (trimmed.StartsWith("level-seed=", StringComparison.Ordinal))
+            {
+                lines[i] = $"level-seed={seed}";
+                done = true;
+                break;
+            }
+        }
+        if (!done) lines.Add($"level-seed={seed}");
+        File.WriteAllLines(PropertiesPath, lines);
+    }
+
+    /// <summary>
+    /// Apply updates to the file. Keys not in <see cref="EditableKeys"/> are
+    /// silently dropped. Lines that already exist are updated in-place to
+    /// preserve order and comments; new keys are appended at the end.
+    /// </summary>
+    public void Update(IDictionary<string, string> updates)
+    {
+        // Filter to allowed keys only.
+        var filtered = updates
+            .Where(kv => EditableKeys.Contains(kv.Key))
+            .ToDictionary(kv => kv.Key, kv => kv.Value, StringComparer.OrdinalIgnoreCase);
+        if (filtered.Count == 0) return;
+
+        var lines = File.Exists(PropertiesPath)
+            ? File.ReadAllLines(PropertiesPath).ToList()
+            : new List<string>();
+
+        var applied = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        for (int i = 0; i < lines.Count; i++)
+        {
+            var raw = lines[i];
+            var trimmed = raw.TrimStart();
+            if (trimmed.Length == 0 || trimmed[0] == '#' || trimmed[0] == '!') continue;
+            var idx = trimmed.IndexOf('=');
+            if (idx < 0) continue;
+            var key = trimmed.Substring(0, idx).Trim();
+            if (filtered.TryGetValue(key, out var newValue))
+            {
+                lines[i] = $"{key}={newValue}";
+                applied.Add(key);
+            }
+        }
+        foreach (var (key, value) in filtered)
+        {
+            if (!applied.Contains(key)) lines.Add($"{key}={value}");
+        }
+        File.WriteAllLines(PropertiesPath, lines);
+    }
+}

server/Services/UpdaterService.cs

@@ -0,0 +1,260 @@
+using BrassAndSigil.Server.Models;
+using System.Text.Json;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Drives a "fetch new manifest, drain players, swap mods, restart MC" workflow.
+/// Single-flight: one update at a time, guarded by a semaphore. State is exposed
+/// so the panel can poll progress; logs go through the existing OnLogLine event
+/// (re-streamed via SSE) so they show up in the live console too.
+/// </summary>
+public sealed class UpdaterService
+{
+    private readonly ServerConfig _config;
+    private readonly string _configPath;
+    private readonly ServerProcess _proc;
+    private readonly Broadcaster _broadcast;
+    private readonly Action<string> _log;
+    private readonly SemaphoreSlim _gate = new(1, 1);
+
+    private CancellationTokenSource? _cts;
+    public UpdateState State { get; private set; } = new();
+
+    public sealed class UpdateState
+    {
+        public bool InProgress      { get; set; }
+        public string Phase         { get; set; } = "idle";
+            // "idle" | "countdown" | "stopping" | "syncing" | "installing_loader" | "starting" | "complete" | "failed" | "cancelled"
+        public int CountdownTotal   { get; set; }
+        public int CountdownRemaining { get; set; }
+        public string? CurrentVersion   { get; set; }
+        public string? AvailableVersion { get; set; }
+        public string? Error            { get; set; }
+        public DateTimeOffset? LastFinishedAt { get; set; }
+    }
+
+    public sealed record CheckResult(string? Current, string? Available, bool NeedsUpdate, string? Error);
+
+    public UpdaterService(ServerConfig config, string configPath,
+                          ServerProcess proc, Broadcaster broadcast,
+                          Action<string> log)
+    {
+        _config = config;
+        _configPath = configPath;
+        _proc = proc;
+        _broadcast = broadcast;
+        _log = log;
+    }
+
+    /// <summary>Lightweight read: compare local pack-version.json to remote manifest.</summary>
+    public async Task<CheckResult> CheckAsync(CancellationToken ct = default)
+    {
+        try
+        {
+            var sync = new ManifestSync();
+            var manifest = await sync.FetchManifestAsync(_config.ManifestUrl, ct);
+            var local = ReadLocalPackVersion(_config.ServerDir);
+            var current = local;
+            var available = manifest.Version;
+            var needs = !string.Equals(current, available, StringComparison.Ordinal);
+            State.CurrentVersion   = current;
+            State.AvailableVersion = available;
+            return new CheckResult(current, available, needs, null);
+        }
+        catch (Exception ex)
+        {
+            return new CheckResult(State.CurrentVersion, State.AvailableVersion, false, ex.Message);
+        }
+    }
+
+    public bool TryCancel()
+    {
+        if (!State.InProgress || _cts is null) return false;
+        // Only meaningful during countdown phase -- a sync mid-flight isn't safely abortable.
+        if (State.Phase != "countdown") return false;
+        _cts.Cancel();
+        return true;
+    }
+
+    /// <summary>
+    /// Run the full update flow. Single-flight -- returns false if one is already running.
+    /// </summary>
+    public async Task<bool> StartAsync(int delaySeconds)
+    {
+        if (!await _gate.WaitAsync(0)) return false;
+        _cts = new CancellationTokenSource();
+        var ct = _cts.Token;
+
+        State = new UpdateState
+        {
+            InProgress = true,
+            Phase = "countdown",
+            CountdownTotal = delaySeconds,
+            CountdownRemaining = delaySeconds,
+            CurrentVersion = State.CurrentVersion,
+            AvailableVersion = State.AvailableVersion,
+        };
+
+        try
+        {
+            // ── 1. Player-facing countdown ──
+            if (delaySeconds > 0 && _proc.IsRunning)
+            {
+                _log($"[update] Announcing restart in {delaySeconds}s.");
+                await _broadcast.SayAsync($"Server will restart in {FormatDuration(delaySeconds)} for an update to v{State.AvailableVersion}.", ct);
+
+                // Run the action-bar countdown + periodic chat warnings + UI ticker
+                // in parallel. Action bar (instead of boss bar) avoids stacking on
+                // top of real boss fight UIs (Ender Dragon, raids, mod bosses).
+                var actionBar = _broadcast.ActionBarCountdownAsync(
+                    "Server restart for update", delaySeconds, ct);
+
+                var warnings = WarnDuringCountdownAsync(delaySeconds, ct);
+
+                // Drive State.CountdownRemaining for the UI poller.
+                var ticker = TickCountdownStateAsync(delaySeconds, ct);
+
+                await Task.WhenAll(actionBar, warnings, ticker);
+            }
+
+            // ── 2. Stop MC ──
+            ct.ThrowIfCancellationRequested();
+            State.Phase = "stopping";
+            _log("[update] Stopping Minecraft for update...");
+            if (_proc.IsRunning)
+            {
+                await _broadcast.SayAsync("Server is restarting now.");
+                await _proc.StopAsync(TimeSpan.FromSeconds(30));
+            }
+
+            // ── 3. Sync mods from manifest ──
+            ct.ThrowIfCancellationRequested();
+            State.Phase = "syncing";
+            _log("[update] Syncing mods from manifest...");
+            var sync = new ManifestSync();
+            var progress = new Progress<string>(msg => _log($"[update]   {msg}"));
+            var result = await sync.SyncAsync(_config.ManifestUrl, _config.ServerDir, progress, ct);
+            _log($"[update] Sync complete: {result.Downloaded} downloaded, {result.Removed} removed.");
+
+            // ── 4. Update NeoForge if loader version changed ──
+            ct.ThrowIfCancellationRequested();
+            var manifest = await sync.FetchManifestAsync(_config.ManifestUrl, ct);
+            if (manifest.Loader is { } loader &&
+                loader.Type.Equals("neoforge", StringComparison.OrdinalIgnoreCase) &&
+                LoaderVersionChanged(_config.ServerDir, loader.Version))
+            {
+                State.Phase = "installing_loader";
+                _log($"[update] Reinstalling NeoForge {loader.Version}...");
+                var nf = new NeoForgeInstaller();
+                var ok = await nf.InstallAsync(loader.Version, _config.ServerDir, _config.JavaPath, progress, ct);
+                if (!ok) throw new InvalidOperationException("NeoForge installer failed.");
+            }
+
+            // ── 5. Start MC ──
+            ct.ThrowIfCancellationRequested();
+            State.Phase = "starting";
+            _log("[update] Starting Minecraft...");
+            _proc.Start();
+            State.CurrentVersion = manifest.Version;
+
+            State.Phase = "complete";
+            State.InProgress = false;
+            State.LastFinishedAt = DateTimeOffset.UtcNow;
+            _log("[update] Update complete.");
+            return true;
+        }
+        catch (OperationCanceledException)
+        {
+            State.Phase = "cancelled";
+            State.InProgress = false;
+            State.LastFinishedAt = DateTimeOffset.UtcNow;
+            _log("[update] Update cancelled.");
+            // If we cancelled during countdown, MC is still running -- leave it alone.
+            return false;
+        }
+        catch (Exception ex)
+        {
+            State.Phase = "failed";
+            State.Error = ex.Message;
+            State.InProgress = false;
+            State.LastFinishedAt = DateTimeOffset.UtcNow;
+            _log($"[update] Failed: {ex.Message}");
+            // Try to bring MC back up if we stopped it but never restarted.
+            if (!_proc.IsRunning)
+            {
+                try { _proc.Start(); _log("[update] Restored Minecraft after failure."); }
+                catch (Exception startEx) { _log($"[update] Restore failed too: {startEx.Message}"); }
+            }
+            return false;
+        }
+        finally
+        {
+            _cts?.Dispose();
+            _cts = null;
+            _gate.Release();
+        }
+    }
+
+    private async Task TickCountdownStateAsync(int total, CancellationToken ct)
+    {
+        for (int sec = total; sec > 0; sec--)
+        {
+            ct.ThrowIfCancellationRequested();
+            State.CountdownRemaining = sec;
+            try { await Task.Delay(1000, ct); }
+            catch (OperationCanceledException) { throw; }
+        }
+        State.CountdownRemaining = 0;
+    }
+
+    private async Task WarnDuringCountdownAsync(int total, CancellationToken ct)
+    {
+        // Periodic chat warnings -- independent of the boss bar (visual-but-missable).
+        // Each milestone fires at an absolute time computed from the start, so the
+        // delays don't accumulate sequentially across the loop iterations.
+        var startUtc = DateTime.UtcNow;
+        var milestones = new[] { 300, 60, 30, 10 };
+        foreach (var m in milestones)
+        {
+            if (m >= total) continue;
+            var fireAt = startUtc.AddSeconds(total - m);
+            var wait = fireAt - DateTime.UtcNow;
+            if (wait > TimeSpan.Zero)
+            {
+                try { await Task.Delay(wait, ct); }
+                catch (OperationCanceledException) { throw; }
+            }
+            try { await _broadcast.SayAsync($"Server restart in {FormatDuration(m)}."); }
+            catch { /* don't bring down the whole update for one failed broadcast */ }
+        }
+    }
+
+    private static bool LoaderVersionChanged(string serverDir, string newVersion)
+    {
+        // Look at the libraries dir for an existing neoforge-<version> path.
+        // If absent or different version, we should re-install.
+        var libsRoot = Path.Combine(serverDir, "libraries", "net", "neoforged", "neoforge");
+        if (!Directory.Exists(libsRoot)) return true;
+        var versions = Directory.EnumerateDirectories(libsRoot).Select(Path.GetFileName).ToList();
+        return !versions.Contains(newVersion);
+    }
+
+    private static string? ReadLocalPackVersion(string serverDir)
+    {
+        var path = Path.Combine(serverDir, "pack-version.json");
+        if (!File.Exists(path)) return null;
+        try
+        {
+            using var doc = JsonDocument.Parse(File.ReadAllText(path));
+            return doc.RootElement.TryGetProperty("version", out var v) ? v.GetString() : null;
+        }
+        catch { return null; }
+    }
+
+    private static string FormatDuration(int seconds)
+    {
+        if (seconds >= 60) return $"{seconds / 60} minute{(seconds / 60 == 1 ? "" : "s")}";
+        return $"{seconds} second{(seconds == 1 ? "" : "s")}";
+    }
+}

server/Services/WhitelistRequestService.cs

@@ -0,0 +1,145 @@
+using System.Text.Json;
+using BrassAndSigil.Server.Models;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Tracks "I want to play" requests from friends, pending admin approval.
+/// State is a flat JSON file in the server dir so it survives daemon restarts
+/// without needing a database. Single-flight gate prevents concurrent-write
+/// corruption when admin and friend act at the same time.
+///
+/// State machine:  (none) -> pending -> approved | denied
+/// "approved" means the admin clicked Approve; the actual /whitelist add
+/// command goes through the existing whitelist endpoint, which removes the
+/// request from the pending list.
+/// </summary>
+public sealed class WhitelistRequestService
+{
+    private readonly ServerConfig _config;
+    private readonly object _lock = new();
+
+    public WhitelistRequestService(ServerConfig config) => _config = config;
+
+    public sealed class Request
+    {
+        public string Username  { get; set; } = "";
+        public string? Message  { get; set; }
+        public string Status    { get; set; } = "pending"; // pending | approved | denied
+        public DateTimeOffset RequestedAt { get; set; }
+        public DateTimeOffset? ResolvedAt { get; set; }
+        public string? RemoteIp { get; set; } // for admin diagnosis if needed
+    }
+
+    private string FilePath =>
+        Path.Combine(Path.GetFullPath(_config.ServerDir), "whitelist-requests.json");
+
+    private List<Request> Load()
+    {
+        try
+        {
+            if (!File.Exists(FilePath)) return new();
+            var text = File.ReadAllText(FilePath);
+            if (string.IsNullOrWhiteSpace(text)) return new();
+            return JsonSerializer.Deserialize<List<Request>>(text, JsonOpts.CaseInsensitive) ?? new();
+        }
+        catch { return new(); }
+    }
+
+    private void Save(List<Request> list)
+    {
+        var text = JsonSerializer.Serialize(list, JsonOpts.Pretty);
+        File.WriteAllText(FilePath, text);
+    }
+
+    public IReadOnlyList<Request> List() { lock (_lock) return Load(); }
+
+    public IReadOnlyList<Request> ListPending()
+    {
+        lock (_lock)
+            return Load().Where(r => r.Status == "pending").ToList();
+    }
+
+    /// <summary>Submit a new request. Idempotent on (username, status=pending) -- won't dupe.</summary>
+    public Request Submit(string username, string? message, string? remoteIp)
+    {
+        lock (_lock)
+        {
+            var list = Load();
+            // Drop any prior request for this username (case-insensitive) so the
+            // most recent one wins regardless of previous state. Keeps the file
+            // from growing if a friend re-requests after a denial.
+            list.RemoveAll(r => r.Username.Equals(username, StringComparison.OrdinalIgnoreCase));
+            var req = new Request
+            {
+                Username    = username,
+                Message     = string.IsNullOrWhiteSpace(message) ? null : message,
+                Status      = "pending",
+                RequestedAt = DateTimeOffset.UtcNow,
+                RemoteIp    = remoteIp,
+            };
+            list.Add(req);
+            Save(list);
+            return req;
+        }
+    }
+
+    /// <summary>
+    /// Effective status for the launcher. If the username is in the actual
+    /// whitelist.json (regardless of whether they ever filed a request), returns
+    /// "approved" -- that's what the friend's launcher cares about. Otherwise
+    /// falls back to whatever request record we have, or "unknown".
+    /// </summary>
+    public string StatusFor(string username)
+    {
+        if (IsActuallyWhitelisted(username)) return "approved";
+        lock (_lock)
+        {
+            var match = Load().FirstOrDefault(r => r.Username.Equals(username, StringComparison.OrdinalIgnoreCase));
+            return match?.Status ?? "unknown";
+        }
+    }
+
+    private bool IsActuallyWhitelisted(string username)
+    {
+        var path = Path.Combine(Path.GetFullPath(_config.ServerDir), "whitelist.json");
+        if (!File.Exists(path)) return false;
+        try
+        {
+            using var doc = JsonDocument.Parse(File.ReadAllText(path));
+            return doc.RootElement.EnumerateArray().Any(e =>
+                e.TryGetProperty("name", out var n) &&
+                string.Equals(n.GetString(), username, StringComparison.OrdinalIgnoreCase));
+        }
+        catch { return false; }
+    }
+
+    public bool MarkApproved(string username) => SetStatus(username, "approved");
+    public bool MarkDenied(string username)   => SetStatus(username, "denied");
+
+    /// <summary>Remove the request entirely (used after the actual /whitelist add fires).</summary>
+    public bool Remove(string username)
+    {
+        lock (_lock)
+        {
+            var list = Load();
+            var removed = list.RemoveAll(r => r.Username.Equals(username, StringComparison.OrdinalIgnoreCase));
+            if (removed > 0) Save(list);
+            return removed > 0;
+        }
+    }
+
+    private bool SetStatus(string username, string status)
+    {
+        lock (_lock)
+        {
+            var list = Load();
+            var match = list.FirstOrDefault(r => r.Username.Equals(username, StringComparison.OrdinalIgnoreCase));
+            if (match is null) return false;
+            match.Status = status;
+            match.ResolvedAt = DateTimeOffset.UtcNow;
+            Save(list);
+            return true;
+        }
+    }
+}

server/Services/WindowsJobObject.cs

@@ -0,0 +1,124 @@
+using System.ComponentModel;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Wraps a Windows Job Object configured with KILL_ON_JOB_CLOSE so that any process
+/// assigned to it dies the moment our process does -- regardless of *how* we died
+/// (X-button on the console, Task Manager End Task, parent BSOD, etc.). Without
+/// this, a Java subprocess can outlive us and keep the server files locked.
+///
+/// On Linux, use systemd's cgroup management instead; the equivalent guarantee
+/// comes for free when the tool runs as a systemd unit.
+/// </summary>
+public sealed class WindowsJobObject : IDisposable
+{
+    private const int JobObjectExtendedLimitInformation = 9;
+    private const uint JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE = 0x2000;
+
+    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
+    private static extern IntPtr CreateJobObject(IntPtr lpJobAttributes, string? lpName);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool SetInformationJobObject(IntPtr hJob, int infoType, IntPtr lpJobObjectInfo, uint cbJobObjectInfoLength);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool AssignProcessToJobObject(IntPtr hJob, IntPtr hProcess);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool CloseHandle(IntPtr hObject);
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct JOBOBJECT_BASIC_LIMIT_INFORMATION
+    {
+        public long PerProcessUserTimeLimit;
+        public long PerJobUserTimeLimit;
+        public uint LimitFlags;
+        public UIntPtr MinimumWorkingSetSize;
+        public UIntPtr MaximumWorkingSetSize;
+        public uint ActiveProcessLimit;
+        public UIntPtr Affinity;
+        public uint PriorityClass;
+        public uint SchedulingClass;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct IO_COUNTERS
+    {
+        public ulong ReadOperationCount;
+        public ulong WriteOperationCount;
+        public ulong OtherOperationCount;
+        public ulong ReadTransferCount;
+        public ulong WriteTransferCount;
+        public ulong OtherTransferCount;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct JOBOBJECT_EXTENDED_LIMIT_INFORMATION
+    {
+        public JOBOBJECT_BASIC_LIMIT_INFORMATION BasicLimitInformation;
+        public IO_COUNTERS IoInfo;
+        public UIntPtr ProcessMemoryLimit;
+        public UIntPtr JobMemoryLimit;
+        public UIntPtr PeakProcessMemoryUsed;
+        public UIntPtr PeakJobMemoryUsed;
+    }
+
+    private IntPtr _handle;
+    private bool _disposed;
+
+    public WindowsJobObject()
+    {
+        if (!OperatingSystem.IsWindows())
+            throw new PlatformNotSupportedException("WindowsJobObject only works on Windows.");
+
+        _handle = CreateJobObject(IntPtr.Zero, null);
+        if (_handle == IntPtr.Zero) throw new Win32Exception(Marshal.GetLastWin32Error(), "CreateJobObject failed");
+
+        var info = new JOBOBJECT_EXTENDED_LIMIT_INFORMATION
+        {
+            BasicLimitInformation = new JOBOBJECT_BASIC_LIMIT_INFORMATION
+            {
+                LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE
+            }
+        };
+        var size = Marshal.SizeOf(info);
+        var ptr = Marshal.AllocHGlobal(size);
+        try
+        {
+            Marshal.StructureToPtr(info, ptr, fDeleteOld: false);
+            if (!SetInformationJobObject(_handle, JobObjectExtendedLimitInformation, ptr, (uint)size))
+                throw new Win32Exception(Marshal.GetLastWin32Error(), "SetInformationJobObject failed");
+        }
+        finally
+        {
+            Marshal.FreeHGlobal(ptr);
+        }
+    }
+
+    public void AssignProcess(Process process)
+    {
+        if (_disposed) throw new ObjectDisposedException(nameof(WindowsJobObject));
+        if (!AssignProcessToJobObject(_handle, process.Handle))
+            throw new Win32Exception(Marshal.GetLastWin32Error(), "AssignProcessToJobObject failed");
+    }
+
+    public void Dispose()
+    {
+        if (_disposed) return;
+        _disposed = true;
+        if (_handle != IntPtr.Zero)
+        {
+            CloseHandle(_handle); // Closing the last handle triggers KILL_ON_JOB_CLOSE
+            _handle = IntPtr.Zero;
+        }
+        GC.SuppressFinalize(this);
+    }
+
+    ~WindowsJobObject() => Dispose();
+}

server/Services/WorldService.cs

@@ -0,0 +1,229 @@
+using System.Text.RegularExpressions;
+using BrassAndSigil.Server.Models;
+
+namespace BrassAndSigil.Server.Services;
+
+/// <summary>
+/// Destructive world operations -- wipe and replace. Always single-flight, always
+/// stops the server first, and offers a rename-as-backup default so an accidental
+/// click doesn't lose data permanently.
+/// </summary>
+public sealed class WorldService
+{
+    private readonly ServerConfig _config;
+    private readonly ServerProcess _proc;
+    private readonly BackupService _backup;
+    private readonly Broadcaster _broadcast;
+    private readonly RconManager _rcon;
+    private readonly BlueMapService? _bluemap;
+    private readonly Action<string> _log;
+    private readonly SemaphoreSlim _lock = new(1, 1);
+
+    public WorldService(ServerConfig config, ServerProcess proc, BackupService backup,
+                        Broadcaster broadcast, RconManager rcon, Action<string> log,
+                        BlueMapService? bluemap = null)
+    {
+        _config = config;
+        _proc = proc;
+        _backup = backup;
+        _broadcast = broadcast;
+        _rcon = rcon;
+        _bluemap = bluemap;
+        _log = log;
+    }
+
+    public sealed record WipeResult(bool Ok, string? BackupName, string? SeedUsed, string? Error);
+
+    /// <summary>
+    /// What seed strategy a wipe should use:
+    /// <list type="bullet">
+    /// <item><c>Keep</c> -- capture the live seed via RCON before wipe and reuse it.</item>
+    /// <item><c>Random</c> -- clear <c>level-seed</c> so MC picks a fresh random one.</item>
+    /// <item><c>Custom</c> -- set <c>level-seed</c> to <see cref="WipeOptions.CustomSeed"/>.</item>
+    /// </list>
+    /// </summary>
+    public enum SeedMode { Keep, Random, Custom }
+
+    public sealed record WipeOptions(bool Backup, SeedMode Mode, string? CustomSeed);
+
+    /// <summary>
+    /// Best-effort lookup of the current world seed. Prefers RCON's <c>seed</c>
+    /// command (always returns the actual generated seed even when
+    /// server.properties has level-seed empty); falls back to the configured
+    /// level-seed value if RCON is unavailable (server stopped, no MC, etc.).
+    /// Returns null when neither is available.
+    /// </summary>
+    public async Task<string?> GetCurrentSeedAsync(CancellationToken ct = default)
+    {
+        if (_proc.IsRunning)
+        {
+            try
+            {
+                var resp = await _rcon.SendCommandAsync("seed", ct);
+                // Format: "Seed: [<number>]"
+                var m = Regex.Match(resp, @"Seed:\s*\[(-?\d+)\]");
+                if (m.Success) return m.Groups[1].Value;
+            }
+            catch { /* fall through to properties */ }
+        }
+        return new ServerPropertiesService(_config).GetLevelSeed();
+    }
+
+    // Caching world size: scanning a large world dir is O(file count). 30 s cache
+    // dampens that to roughly once per status poll cycle on busy panels.
+    private long _cachedSize;
+    private DateTime _cachedAt = DateTime.MinValue;
+
+    public long GetWorldSizeBytes()
+    {
+        if ((DateTime.UtcNow - _cachedAt) < TimeSpan.FromSeconds(30)) return _cachedSize;
+        var levelName = ReadLevelName(_config.ServerDir) ?? "world";
+        var worldDir = Path.Combine(Path.GetFullPath(_config.ServerDir), levelName);
+        if (!Directory.Exists(worldDir)) { _cachedSize = 0; _cachedAt = DateTime.UtcNow; return 0; }
+        long total = 0;
+        try
+        {
+            foreach (var f in Directory.EnumerateFiles(worldDir, "*", SearchOption.AllDirectories))
+            {
+                try { total += new FileInfo(f).Length; } catch { }
+            }
+        }
+        catch { }
+        _cachedSize = total;
+        _cachedAt = DateTime.UtcNow;
+        return total;
+    }
+
+    /// <summary>
+    /// Stop the server, optionally archive the world via BackupService, delete the
+    /// world folder(s), apply the chosen seed strategy, then restart. Backups go
+    /// to the configured backup dir (typically a slower-but-bigger drive) rather
+    /// than next to the world dir.
+    /// </summary>
+    public async Task<WipeResult> WipeWorldAsync(WipeOptions options, int warningSeconds = 30, CancellationToken ct = default)
+    {
+        if (!await _lock.WaitAsync(0, ct))
+            return new WipeResult(false, null, null, "Another wipe is already in progress.");
+
+        try
+        {
+            var serverDir = Path.GetFullPath(_config.ServerDir);
+            var levelName = ReadLevelName(serverDir) ?? "world";
+            var primaryWorld = Path.Combine(serverDir, levelName);
+            var props = new ServerPropertiesService(_config);
+
+            // ── Decide what seed the new world will use, BEFORE we stop the server ──
+            // Keep mode needs RCON, which only works while MC is alive.
+            string seedToWrite;     // value for level-seed= line; "" means random
+            string? capturedSeed = null;
+            switch (options.Mode)
+            {
+                case SeedMode.Keep:
+                    capturedSeed = await GetCurrentSeedAsync(ct);
+                    if (string.IsNullOrEmpty(capturedSeed))
+                    {
+                        return new WipeResult(false, null, null,
+                            "Couldn't read current seed (RCON unreachable + level-seed empty). Stop the server, set level-seed manually, or pick Random/Custom.");
+                    }
+                    seedToWrite = capturedSeed;
+                    _log($"[wipe] Keep-seed mode: captured current seed {capturedSeed} for reuse.");
+                    break;
+                case SeedMode.Custom:
+                    var custom = options.CustomSeed?.Trim() ?? "";
+                    if (string.IsNullOrEmpty(custom))
+                        return new WipeResult(false, null, null, "Custom seed mode selected but no seed provided.");
+                    seedToWrite = custom;
+                    _log($"[wipe] Custom-seed mode: new world will use seed {custom}.");
+                    break;
+                default: // Random
+                    seedToWrite = "";
+                    _log("[wipe] Random-seed mode: clearing level-seed so MC generates a fresh seed.");
+                    break;
+            }
+
+            // Loud, urgent player warning before any irreversible action -- wipe is
+            // destructive even with a backup (admins still need to restore manually).
+            if (warningSeconds > 0 && _proc.IsRunning)
+            {
+                _log($"[wipe] Announcing {warningSeconds}s wipe warning to players...");
+                try
+                {
+                    await _broadcast.SayAsync(
+                        $"WORLD WIPE in {warningSeconds} seconds. Disconnect now if you want to keep your current world!", ct);
+                    await _broadcast.ActionBarCountdownAsync("WORLD WIPING", warningSeconds, ct);
+                    await _broadcast.SayAsync("Wiping world now.");
+                }
+                catch (OperationCanceledException) { throw; }
+                catch { /* don't abort wipe over a broadcast error */ }
+            }
+
+            string? backupName = null;
+            if (options.Backup && Directory.Exists(primaryWorld))
+            {
+                _log("[wipe] Creating backup before wipe...");
+                // flush:true here -- we're about to delete the world. Capture every block
+                // and every move up to right now, even at the cost of a tick spike.
+                var br = await _backup.CreateAsync("pre-wipe", flush: true, ct: ct);
+                if (!br.Ok)
+                    return new WipeResult(false, null, null, $"Backup failed: {br.Error}. Wipe aborted to preserve data.");
+                backupName = br.Name;
+            }
+
+            if (_proc.IsRunning)
+            {
+                _log("[wipe] Stopping server...");
+                await _proc.StopAsync(TimeSpan.FromSeconds(30), ct);
+            }
+
+            if (Directory.Exists(primaryWorld))
+            {
+                _log($"[wipe] Deleting {primaryWorld}");
+                Directory.Delete(primaryWorld, recursive: true);
+            }
+            // Legacy sibling dirs (rare on modern NeoForge but cheap to handle)
+            foreach (var altSuffix in new[] { "_nether", "_the_end" })
+            {
+                var altDir = Path.Combine(serverDir, levelName + altSuffix);
+                if (!Directory.Exists(altDir)) continue;
+                _log($"[wipe] Deleting {altDir}");
+                Directory.Delete(altDir, recursive: true);
+            }
+
+            // Apply the seed AFTER deletion but BEFORE restart -- MC reads
+            // server.properties at startup to determine the new world's seed.
+            props.SetLevelSeed(seedToWrite);
+
+            // Map output for the now-deleted world is stale -- clear it so the next
+            // render starts fresh against the new terrain.
+            _bluemap?.ClearRenderOutput();
+
+            _log("[wipe] World wiped. Restarting server -- Minecraft will generate a fresh world.");
+            _proc.Start();
+            // For Random mode we don't know the exact new seed yet (MC picks at startup);
+            // return the level-seed value we wrote, which is "" for random.
+            return new WipeResult(true, backupName, string.IsNullOrEmpty(seedToWrite) ? null : seedToWrite, null);
+        }
+        catch (Exception ex)
+        {
+            _log($"[wipe] Failed: {ex.Message}");
+            try { if (!_proc.IsRunning) _proc.Start(); } catch { }
+            return new WipeResult(false, null, null, ex.Message);
+        }
+        finally
+        {
+            _lock.Release();
+        }
+    }
+
+    private static string? ReadLevelName(string serverDir)
+    {
+        var path = Path.Combine(serverDir, "server.properties");
+        if (!File.Exists(path)) return null;
+        foreach (var line in File.ReadAllLines(path))
+        {
+            if (line.StartsWith("level-name=", StringComparison.Ordinal))
+                return line.Substring("level-name=".Length).Trim();
+        }
+        return null;
+    }
+}

server/deploy/Caddyfile

@@ -0,0 +1,50 @@
+# Caddyfile for the brass-sigil-server web panel.
+#
+# Caddy auto-fetches and renews a Let's Encrypt cert for your domain,
+# so HTTPS just works once DNS is pointed at the server and ports 80 + 443
+# are open.
+#
+# Prereqs:
+#   1. A domain name (e.g. panel.example.com) with an A/AAAA record pointing
+#      at this server's public IP. Let's Encrypt does NOT issue certs for
+#      raw IPs -- you need a hostname.
+#   2. Inbound 80 (for the HTTP-01 ACME challenge) and 443 (for the panel)
+#      open in your firewall and in any cloud security group.
+#   3. Caddy installed:
+#        sudo apt install caddy            # Debian / Ubuntu
+#        brew install caddy                # macOS
+#        winget install CaddyServer.Caddy  # Windows
+#   4. brass-sigil-server running on localhost:8080 with webHost: localhost
+#      and webPassword set (use `brass-sigil-server set-password` if you
+#      haven't already).
+#
+# Install:
+#   Linux package: replace /etc/caddy/Caddyfile with this file, then
+#     sudo systemctl reload caddy
+#   Manual:        caddy run --config Caddyfile
+
+panel.example.com {
+    encode gzip
+
+    reverse_proxy localhost:8080 {
+        # SSE log stream uses chunked streaming responses -- Caddy must not
+        # buffer them, otherwise console updates arrive in batches every minute
+        # instead of in real time.
+        flush_interval -1
+
+        # Pass the real client IP through. brass-sigil-server's ForwardedHeaders
+        # middleware honours this so the per-IP login rate limit partitions
+        # correctly (10 attempts / minute / IP).
+        header_up X-Forwarded-For {remote_host}
+        header_up X-Real-IP       {remote_host}
+    }
+
+    # Sensible hardening defaults.
+    header {
+        Strict-Transport-Security "max-age=31536000; includeSubDomains"
+        X-Content-Type-Options    "nosniff"
+        X-Frame-Options           "DENY"
+        Referrer-Policy           "strict-origin-when-cross-origin"
+        -Server
+    }
+}

server/deploy/bns-admin.sijbers.uk.conf

@@ -0,0 +1,27 @@
+# /etc/apache2/sites-available/bns-admin.sijbers.uk.conf
+#
+# Reverse-proxy vhost for the brass-sigil-server admin panel.
+# certbot will manage the SSL config (certificate paths, redirect from :80, etc.)
+# when run as: sudo certbot --apache -d bns-admin.sijbers.uk
+
+<VirtualHost *:80>
+    ServerName bns-admin.sijbers.uk
+
+    ProxyPreserveHost On
+    ProxyRequests Off
+
+    # SSE log stream needs streaming responses, not buffered ones.
+    SetEnv no-gzip 1
+    SetEnv proxy-sendcl 1
+
+    # `flushpackets=on` is the SSE-critical bit on Apache -- pushes each chunk
+    # straight through instead of batching for ~60 s.
+    ProxyPass        / http://127.0.0.1:8080/ flushpackets=on keepalive=On
+    ProxyPassReverse / http://127.0.0.1:8080/
+
+    # So brass-sigil-server's rate limiter sees the real client IP, not 127.0.0.1.
+    RequestHeader set X-Forwarded-Proto "https"
+
+    ErrorLog  ${APACHE_LOG_DIR}/bns-admin.sijbers.uk-error.log
+    CustomLog ${APACHE_LOG_DIR}/bns-admin.sijbers.uk-access.log combined
+</VirtualHost>

server/deploy/brass-and-sigil.html

@@ -0,0 +1,284 @@
+<!DOCTYPE HTML>
+<html lang="en">
+
+<head>
+	<meta charset="UTF-8">
+	<meta http-equiv="X-UA-Compatible" content="IE=edge">
+	<meta name="viewport" content="width=device-width, initial-scale=1.0">
+	<title>Brass &amp; Sigil Launcher -- Matt Sijbers</title>
+	<meta name="description" content="A private custom Minecraft Java Edition launcher for the Brass & Sigil modpack -- built in C# / .NET 8 / Avalonia." />
+	<link rel="icon" href="/images/favicon-light.ico" media="(prefers-color-scheme: light)" type="image/x-icon" />
+	<link rel="icon" href="/images/favicon-dark.ico" media="(prefers-color-scheme: dark)" type="image/x-icon" />
+	<link rel="stylesheet" href="css/matt.css">
+	<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
+	<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.3/css/all.min.css" />
+	<style>
+		html, body {
+			background: var(--color-primary-darker-10);
+			overflow: auto;
+			height: auto;
+			min-height: 100vh;
+			max-height: none;
+		}
+		.page-wrap {
+			max-width: 900px;
+			margin: 0 auto;
+			padding: clamp(20px, 5vw, 60px) clamp(16px, 5vw, 32px) 80px;
+		}
+		.back-link {
+			display: inline-flex;
+			align-items: center;
+			gap: 8px;
+			margin-bottom: 24px;
+			font-size: 0.95em;
+		}
+		.hero {
+			padding: clamp(20px, 4vw, 36px);
+			margin-bottom: 24px;
+		}
+		.hero h1 {
+			font-size: clamp(1.6em, 6vw, 2.6em);
+			text-transform: uppercase;
+			margin: 0 0 8px;
+		}
+		.hero .subtitle {
+			color: var(--color-secondary-text);
+			font-size: clamp(0.9em, 3vw, 1.1em);
+			margin: 0;
+		}
+		.tag-row {
+			display: flex;
+			flex-wrap: wrap;
+			gap: 8px;
+			margin-top: 18px;
+		}
+		.tag {
+			background: var(--color-primary-darker-20);
+			color: var(--color-primary-text);
+			padding: 6px 12px;
+			border-radius: 999px;
+			font-size: 0.85em;
+			font-weight: 500;
+		}
+		.action-row {
+			display: flex;
+			flex-wrap: wrap;
+			gap: 12px;
+			margin-top: 22px;
+		}
+		.action-btn {
+			display: inline-flex;
+			align-items: center;
+			gap: 8px;
+			background: var(--color-accent);
+			color: #fff !important;
+			padding: 10px 18px;
+			border-radius: 8px;
+			font-weight: 600;
+			font-size: 0.95em;
+			text-decoration: none;
+			transition: background 0.15s linear, transform 0.1s linear;
+		}
+		.action-btn:hover {
+			background: var(--color-accent-lighter-10);
+			transform: translateY(-1px);
+		}
+		.action-btn.secondary {
+			background: var(--color-primary-darker-20);
+			color: var(--color-primary-text) !important;
+		}
+		.action-btn.secondary:hover {
+			background: var(--color-primary-darker-30);
+		}
+		.whitelist-note {
+			margin: 18px 0 0;
+			padding: 10px 14px;
+			background: var(--color-primary-darker-10);
+			border-left: 3px solid var(--color-accent);
+			border-radius: 6px;
+			color: var(--color-secondary-text);
+			font-size: 0.9em;
+			line-height: 1.45;
+		}
+		.whitelist-note i { color: var(--color-accent); margin-right: 6px; }
+		.section {
+			padding: clamp(18px, 3.5vw, 28px);
+			margin-bottom: 18px;
+		}
+		.section h2 {
+			margin-top: 0;
+			margin-bottom: 12px;
+		}
+		.section p {
+			line-height: 1.55;
+			color: var(--color-primary-text);
+		}
+		.facts {
+			display: grid;
+			grid-template-columns: 1fr 1fr;
+			gap: 14px;
+			margin-top: 8px;
+		}
+		.fact {
+			background: var(--color-primary-darker-10);
+			border-radius: 12px;
+			padding: 14px 18px;
+		}
+		.fact .label {
+			font-size: 0.78em;
+			color: var(--color-secondary-text);
+			text-transform: uppercase;
+			letter-spacing: 0.05em;
+			margin: 0 0 4px;
+		}
+		.fact .value {
+			font-family: "Ubuntu", sans-serif;
+			font-weight: 500;
+			color: var(--color-primary-text);
+			margin: 0;
+		}
+		@media (max-width: 540px) {
+			.facts { grid-template-columns: 1fr; }
+		}
+		ul.feature-list {
+			padding-left: 1.25em;
+			margin: 4px 0 0;
+		}
+		ul.feature-list li {
+			color: var(--color-primary-text);
+			line-height: 1.5;
+			margin: 4px 0;
+		}
+		footer.page-footer {
+			color: var(--color-secondary-text);
+			font-size: 0.85em;
+			text-align: center;
+			margin-top: 40px;
+		}
+	</style>
+</head>
+
+<body>
+	<div class="page-wrap">
+		<a href="/matt#projects" class="back-link"><i class="fa fa-arrow-left"></i> Back to portfolio</a>
+
+		<div class="bevel hero">
+			<h1>Brass &amp; Sigil Launcher</h1>
+			<p class="subtitle">A private custom Minecraft Java Edition launcher for a small friend group.</p>
+			<div class="tag-row">
+				<span class="tag">C# / .NET 8</span>
+				<span class="tag">Avalonia</span>
+				<span class="tag">CmlLib.Core</span>
+				<span class="tag">Single-file Windows</span>
+				<span class="tag">Private project</span>
+			</div>
+			<div class="action-row">
+				<a class="action-btn" href="/pack/BrassAndSigil-Launcher.exe">
+					<i class="fa fa-download"></i> Download launcher
+				</a>
+				<a class="action-btn secondary" href="https://sijbers.uk:8443/projects/BS/repos/brass-and-sigil-launcher/browse"
+				   target="_blank" rel="noopener noreferrer">
+					<i class="fa fa-code"></i> View source code
+				</a>
+				<a class="action-btn secondary" href="/matt#projects">
+					<i class="fa fa-user"></i> Developer portfolio
+				</a>
+			</div>
+			<p class="whitelist-note">
+				<i class="fa fa-info-circle"></i>
+				You'll need to be whitelisted on the server to actually join &mdash; message Matt with your Minecraft username.
+			</p>
+		</div>
+
+		<div class="bevel section">
+			<h2>About the project</h2>
+			<p>
+				Brass &amp; Sigil is a private Minecraft modpack centred on the Create mod, aeronautics, tech and magic mods,
+				with Distant Horizons for far-render exploration. This launcher is the desktop client built specifically
+				to distribute the pack to a small friend group (under 50 players, no public release).
+			</p>
+			<p>
+				The launcher is a native Windows application written in C# on .NET 8, using the Avalonia UI framework.
+				It ships as a single self-contained executable so friends can just download and run it &mdash; no installer,
+				no .NET runtime to install, no separate config files.
+			</p>
+		</div>
+
+		<div class="bevel section">
+			<h2>What it does</h2>
+			<ul class="feature-list">
+				<li>Fetches a JSON manifest from a self-hosted server and syncs the modpack files (mods, configs, resourcepacks) to the player's local install directory, using SHA-1 hashing so only changed files are downloaded.</li>
+				<li>Authenticates the player with their own personal Microsoft account via the standard MSAL OAuth flow, so only legitimate Minecraft Java Edition owners can sign in.</li>
+				<li>Installs the right Minecraft version and Forge loader, then launches the game with the configured memory and the player's session.</li>
+				<li>Auto-updates the modpack on every launch when the manifest changes &mdash; players never have to manually install or update mods.</li>
+			</ul>
+		</div>
+
+		<div class="bevel section">
+			<h2>Technical details</h2>
+			<div class="facts">
+				<div class="fact">
+					<p class="label">Language</p>
+					<p class="value">C# (.NET 8)</p>
+				</div>
+				<div class="fact">
+					<p class="label">UI Framework</p>
+					<p class="value">Avalonia 12</p>
+				</div>
+				<div class="fact">
+					<p class="label">Minecraft auth</p>
+					<p class="value">CmlLib.Core.Auth.Microsoft</p>
+				</div>
+				<div class="fact">
+					<p class="label">Game launching</p>
+					<p class="value">CmlLib.Core 4.x + Forge installer</p>
+				</div>
+				<div class="fact">
+					<p class="label">Distribution</p>
+					<p class="value">Single-file self-contained .exe</p>
+				</div>
+				<div class="fact">
+					<p class="label">Audience</p>
+					<p class="value">Private friend group (&lt; 50)</p>
+				</div>
+			</div>
+		</div>
+
+		<div class="bevel section">
+			<h2>Privacy &amp; data</h2>
+			<p>
+				The launcher does not collect, store, or transmit any user data beyond what the standard Microsoft and
+				Minecraft authentication flows require. Auth tokens are cached locally on the player's machine via the
+				MSAL token cache &mdash; no telemetry, no analytics, no third-party services beyond Microsoft and Mojang.
+			</p>
+			<p>
+				The modpack manifest and mod files are served from a self-hosted Linux server that I personally operate.
+			</p>
+		</div>
+
+		<div class="bevel section">
+			<h2>Status</h2>
+			<p>
+				Active development. The launcher is functional end-to-end (manifest sync, Microsoft auth, Forge install,
+				game launch) and is currently being prepared for distribution to a small group of friends.
+			</p>
+			<p>
+				Source code is publicly available, MIT-licensed, on my self-hosted Bitbucket:
+				<a href="https://sijbers.uk:8443/projects/BS/repos/brass-and-sigil-launcher/browse"
+				   target="_blank" rel="noopener noreferrer">sijbers.uk:8443/.../brass-and-sigil-launcher</a>.
+			</p>
+		</div>
+
+		<div class="bevel section" style="text-align: center; font-size: 0.85em;">
+			<p style="margin: 0; color: var(--color-secondary-text); letter-spacing: 0.04em;">
+				NOT AN OFFICIAL MINECRAFT PRODUCT. NOT APPROVED BY OR ASSOCIATED WITH MOJANG OR MICROSOFT.
+			</p>
+		</div>
+
+		<footer class="page-footer">
+			Brass &amp; Sigil Launcher &mdash; a private project by <a href="/matt">Matt Sijbers</a>.
+		</footer>
+	</div>
+</body>
+
+</html>

server/deploy/brass-sigil-server.service

@@ -0,0 +1,26 @@
+[Unit]
+Description=Brass & Sigil Minecraft server (with web admin panel)
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=matt
+Group=matt
+WorkingDirectory=/home/matt/brass-sigil-server
+ExecStart=/home/matt/brass-sigil-server/brass-sigil-server run
+Restart=on-failure
+RestartSec=10s
+
+# Give the JVM enough room to start up gracefully on Stop (sends "stop" to MC,
+# waits for clean shutdown, then escalates to SIGTERM/SIGKILL).
+TimeoutStopSec=60s
+KillMode=mixed
+
+# Tighten attack surface -- typical for a service running as a regular user.
+PrivateTmp=true
+ProtectSystem=full
+NoNewPrivileges=true
+
+[Install]
+WantedBy=multi-user.target

server/deploy/cleanup-sudo.sh

@@ -0,0 +1,105 @@
+#!/usr/bin/env bash
+# Sudo cleanup script -- review before running.
+# Removes dormant game servers (ARK, Valheim, Terraria), trims journald logs,
+# caps snap revision retention. Does NOT touch Bitbucket, TeamViewer, or the
+# matt-wakeford.co.uk / sijbers.uk / diceheart.com websites.
+#
+# Run with:  sudo bash /tmp/cleanup-sudo.sh
+#
+# Set -e: abort on first error so we don't cascade-damage state.
+set -euo pipefail
+
+echo "=== Pre-cleanup disk ==="
+df -h / | grep -v Filesystem
+
+# ────────────────────────────────────────────────
+# 1. ARK server -- install, user, broken systemd unit
+# ────────────────────────────────────────────────
+echo
+echo "=== ARK ==="
+if systemctl list-unit-files ark.service &>/dev/null; then
+    echo "  Disabling ark.service"
+    systemctl disable --now ark.service 2>/dev/null || true
+fi
+if [[ -f /lib/systemd/system/ark.service ]]; then
+    echo "  Removing /lib/systemd/system/ark.service"
+    rm -f /lib/systemd/system/ark.service
+fi
+if [[ -f /etc/systemd/system/ark.service ]]; then
+    echo "  Removing /etc/systemd/system/ark.service"
+    rm -f /etc/systemd/system/ark.service
+fi
+if id ark &>/dev/null; then
+    # Make sure no processes are running as ark before userdel.
+    pkill -u ark 2>/dev/null || true
+    sleep 1
+    echo "  Removing 'ark' user + home"
+    userdel -r ark 2>/dev/null || userdel ark
+fi
+
+# ────────────────────────────────────────────────
+# 2. Valheim (vhserver) -- LGSM stack
+# ────────────────────────────────────────────────
+echo
+echo "=== Valheim (vhserver) ==="
+if id vhserver &>/dev/null; then
+    pkill -u vhserver 2>/dev/null || true
+    sleep 1
+    echo "  Removing 'vhserver' user + home (incl. orphaned LGSM backups)"
+    userdel -r vhserver 2>/dev/null || userdel vhserver
+fi
+
+# ────────────────────────────────────────────────
+# 3. Terraria -- empty home, never used
+# ────────────────────────────────────────────────
+echo
+echo "=== Terraria ==="
+if id Terraria &>/dev/null; then
+    pkill -u Terraria 2>/dev/null || true
+    echo "  Removing 'Terraria' user + home"
+    userdel -r Terraria 2>/dev/null || userdel Terraria
+fi
+
+# ────────────────────────────────────────────────
+# 4. systemd reload to forget the gone units
+# ────────────────────────────────────────────────
+echo
+echo "=== systemctl daemon-reload ==="
+systemctl daemon-reload
+systemctl reset-failed 2>/dev/null || true
+
+# ────────────────────────────────────────────────
+# 5. journald -- cap to 500 MB
+# ────────────────────────────────────────────────
+echo
+echo "=== journald ==="
+echo "  Trimming /var/log/journal to 500 MB"
+journalctl --vacuum-size=500M
+
+# ────────────────────────────────────────────────
+# 6. snap -- only keep current + 1 prior revision
+# ────────────────────────────────────────────────
+echo
+echo "=== snap retention ==="
+echo "  Setting refresh.retain=2 (snap will auto-clean older revs over time)"
+snap set system refresh.retain=2
+
+# Force-clean orphaned _old.snap files older than 30 days. Snap will redo
+# this organically but we can prod it now to reclaim immediately.
+echo "  Forcing snap to drop disabled revisions"
+for snap in $(snap list --all | awk '/disabled/{print $1, $3}'); do
+    if [[ "$snap" == "disabled" ]]; then continue; fi
+done
+# Easier path: ask snap directly.
+LANG=C snap list --all | awk '/disabled/{print $1, $3}' | \
+    while read -r name rev; do
+        echo "    snap remove --revision=$rev $name"
+        snap remove --revision="$rev" "$name" || true
+    done
+
+# ────────────────────────────────────────────────
+echo
+echo "=== Post-cleanup disk ==="
+df -h / | grep -v Filesystem
+echo
+echo "Done. Bitbucket, TeamViewer, and websites untouched."

server/deploy/manifest.json

@@ -0,0 +1,135 @@
+{
+    "name":  "Brass and Sigil",
+    "version":  "0.6.1",
+    "minecraft":  {
+                      "version":  "1.21.1"
+                  },
+    "loader":  {
+                   "type":  "neoforge",
+                   "version":  "21.1.228"
+               },
+    "files":  [
+                  {
+                      "path":  "mods/create-1.21.1-6.0.10.jar",
+                      "url":  "https://cdn.modrinth.com/data/LNytGWDc/versions/UjX6dr61/create-1.21.1-6.0.10.jar",
+                      "sha1":  "0e97e49837bed766e6f28a4c95b04885d6acc353",
+                      "size":  19123767
+                  },
+                  {
+                      "path":  "mods/create-aeronautics-bundled-1.21.1-1.2.1.jar",
+                      "url":  "https://cdn.modrinth.com/data/oWaK0Q19/versions/YhZLrAFC/create-aeronautics-bundled-1.21.1-1.2.1.jar",
+                      "sha1":  "fdf1ae69e8b6437e0196b3a35dd2325aa904aba9",
+                      "size":  33030286
+                  },
+                  {
+                      "path":  "mods/sable-neoforge-1.21.1-1.2.2.jar",
+                      "url":  "https://cdn.modrinth.com/data/T9PomCSv/versions/3FMsUjO4/sable-neoforge-1.21.1-1.2.2.jar",
+                      "sha1":  "c5ecd3fcf60a31d84112c708abe29e341b2d1b73",
+                      "size":  12719293
+                  },
+                  {
+                      "path":  "mods/createbigcannons-5.11.3+mc.1.21.1.jar",
+                      "url":  "https://cdn.modrinth.com/data/GWp4jCJj/versions/bsGaXKEd/createbigcannons-5.11.3%2Bmc.1.21.1.jar",
+                      "sha1":  "8b61fa850e260bdeb5d360576123f98c260afa50",
+                      "size":  3715787
+                  },
+                  {
+                      "path":  "mods/tfmg-1.2.0.jar",
+                      "url":  "https://cdn.modrinth.com/data/USgVjXsk/versions/uDi14nbt/tfmg-1.2.0.jar",
+                      "sha1":  "b520f3687f60a69eb265ff5b9a16759b9e124103",
+                      "size":  4924243
+                  },
+                  {
+                      "path":  "mods/DistantHorizons-3.0.2-b-1.21.1-fabric-neoforge.jar",
+                      "url":  "https://cdn.modrinth.com/data/uCdwusMi/versions/KkaaQtTD/DistantHorizons-3.0.2-b-1.21.1-fabric-neoforge.jar",
+                      "sha1":  "1ff0a8920e52add541471f7b32d0d389997145ba",
+                      "size":  30019727
+                  },
+                  {
+                      "path":  "mods/sodium-neoforge-0.6.13+mc1.21.1.jar",
+                      "url":  "https://cdn.modrinth.com/data/AANobbMI/versions/Pb3OXVqC/sodium-neoforge-0.6.13%2Bmc1.21.1.jar",
+                      "sha1":  "38af70fa4dc4b2aaac636e92fdba3bedd5a025e1",
+                      "size":  1162994
+                  },
+                  {
+                      "path":  "mods/iris-neoforge-1.8.12+mc1.21.1.jar",
+                      "url":  "https://cdn.modrinth.com/data/YL57xq9U/versions/t3ruzodq/iris-neoforge-1.8.12%2Bmc1.21.1.jar",
+                      "sha1":  "a3e6355915c7d3b2bc392724795113e51d289378",
+                      "size":  2438548
+                  },
+                  {
+                      "path":  "mods/modernfix-neoforge-5.27.4+mc1.21.1.jar",
+                      "url":  "https://cdn.modrinth.com/data/nmDcB62a/versions/6U8JVjdw/modernfix-neoforge-5.27.4%2Bmc1.21.1.jar",
+                      "sha1":  "2f39363f0d6d5a5ccc2a9e0f50ad3385611c3cb7",
+                      "size":  562051
+                  },
+                  {
+                      "path":  "mods/ferritecore-7.0.3-neoforge.jar",
+                      "url":  "https://cdn.modrinth.com/data/uXXizFIs/versions/x7kQWVju/ferritecore-7.0.3-neoforge.jar",
+                      "sha1":  "9563692efb708b6b568df27a01ec52f6311928ef",
+                      "size":  121559
+                  },
+                  {
+                      "path":  "mods/architectury-13.0.8-neoforge.jar",
+                      "url":  "https://cdn.modrinth.com/data/lhGA9TYQ/versions/ZxYGwlk0/architectury-13.0.8-neoforge.jar",
+                      "sha1":  "6ca11d3cc136bf69bb8f4d56982481eb85b5100b",
+                      "size":  584004
+                  },
+                  {
+                      "path":  "mods/rhino-2101.2.7-build.81.jar",
+                      "url":  "https://cdn.modrinth.com/data/sk9knFPE/versions/ZdLtebKH/rhino-2101.2.7-build.81.jar",
+                      "sha1":  "480235a9f7749f68ce6fec3b9c3cac3428b92a4a",
+                      "size":  882033
+                  },
+                  {
+                      "path":  "mods/ritchiesprojectilelib-2.1.2+mc.1.21.1-neoforge.jar",
+                      "url":  "https://cdn.modrinth.com/data/B3pb093D/versions/hZ6B2Z0x/ritchiesprojectilelib-2.1.2%2Bmc.1.21.1-neoforge.jar",
+                      "sha1":  "ec2e4996f8bee8714173e603e379fef8a6901765",
+                      "size":  76369
+                  },
+                  {
+                      "path":  "mods/kubejs-neoforge-2101.7.2-build.363.jar",
+                      "url":  "https://cdn.modrinth.com/data/umyGl7zF/versions/Fe9CjPws/kubejs-neoforge-2101.7.2-build.363.jar",
+                      "sha1":  "d4e88254e8c26687d4c6aeb4dfa9c2ad70f260a2",
+                      "size":  2270442
+                  },
+                  {
+                      "path":  "mods/jei-1.21.1-neoforge-19.27.0.340.jar",
+                      "url":  "https://cdn.modrinth.com/data/u6dRKJwZ/versions/YAcQ6elZ/jei-1.21.1-neoforge-19.27.0.340.jar",
+                      "sha1":  "27d0d85e7e32e926fc3664ab6815df5cdabb7941",
+                      "size":  1529391
+                  },
+                  {
+                      "path":  "mods/Jade-1.21.1-NeoForge-15.10.5.jar",
+                      "url":  "https://cdn.modrinth.com/data/nvQzSEkH/versions/yd8FKCmx/Jade-1.21.1-NeoForge-15.10.5.jar",
+                      "sha1":  "d5bf134b3dbde9f5258666823900e21341dc0a50",
+                      "size":  725742
+                  },
+                  {
+                      "path":  "mods/Chunky-NeoForge-1.4.23.jar",
+                      "url":  "https://cdn.modrinth.com/data/fALzjamp/versions/LuFhm4eU/Chunky-NeoForge-1.4.23.jar",
+                      "sha1":  "ab0c74743a653020fe2dfc4986b43e893947f3e9",
+                      "size":  340572
+                  },
+                  {
+                      "path":  "mods/ftb-library-neoforge-2101.1.31.jar",
+                      "url":  "https://mediafilez.forgecdn.net/files/7746/959/ftb-library-neoforge-2101.1.31.jar",
+                      "sha1":  "686d4e784c28c14f7760cc22b2de6a8573b56b74",
+                      "size":  1411181
+                  },
+                  {
+                      "path":  "mods/ftb-teams-neoforge-2101.1.9.jar",
+                      "url":  "https://mediafilez.forgecdn.net/files/7369/21/ftb-teams-neoforge-2101.1.9.jar",
+                      "sha1":  "328e04bf1a445870aacea8fe7637670f84272a8f",
+                      "size":  291847
+                  },
+                  {
+                      "path":  "mods/ftb-chunks-neoforge-2101.1.14.jar",
+                      "url":  "https://mediafilez.forgecdn.net/files/7608/681/ftb-chunks-neoforge-2101.1.14.jar",
+                      "sha1":  "908b63b11d0e00ae6c9557d3fe6440bdbcf21bb7",
+                      "size":  642340
+                  }
+              ],
+    "launcherVersion":  "0.1.0",
+    "launcherUrl":  "https://sijbers.uk/pack/BrassAndSigil-Launcher.exe"
+}

server/deploy/server-config.example.json

@@ -0,0 +1,12 @@
+{
+  "manifestUrl": "https://sijbers.uk/pack/manifest.json",
+  "serverDir": "./server",
+  "javaPath": "java",
+  "memoryMB": 8192,
+  "webPort": 8080,
+  "webHost": "localhost",
+  "webPassword": null,
+  "rconPort": 25575,
+  "rconPassword": "",
+  "acceptEula": false
+}

server/wwwroot/app.js

@@ -0,0 +1,42 @@
+"use strict";
+
+import { tickStatus, tickPlayers, tickWhitelist, refreshWhitelistSoon } from "./modules/panels.js";
+import { setupConsole } from "./modules/console.js";
+import { setupAutocomplete } from "./modules/autocomplete.js";
+import { setupWhitelistActions } from "./modules/whitelist.js";
+import { setupServerControls } from "./modules/serverControls.js";
+import { setupPregen } from "./modules/pregen.js";
+import { setupAuth } from "./modules/auth.js";
+import { setupUpdate } from "./modules/update.js";
+import { setupDanger } from "./modules/danger.js";
+import { setupBackup } from "./modules/backup.js";
+import { setupModalTriggers } from "./modules/modal.js";
+import { setupSettings } from "./modules/settings.js";
+import { setupMap } from "./modules/map.js";
+
+setupModalTriggers();
+setupAuth();
+setupConsole();
+setupAutocomplete();
+setupWhitelistActions(refreshWhitelistSoon);
+setupServerControls();
+setupPregen();
+setupUpdate();
+setupBackup();
+setupDanger();
+setupSettings();
+setupMap();
+
+// First paint
+tickStatus();
+tickPlayers();
+tickWhitelist();
+
+// Polling cadence:
+//   status   3 s -- pid/uptime/pack version (cheap, doesn't change much)
+//   players 10 s -- RCON `list` call; players join/leave infrequently
+//   whitelist 30 s -- file read; mostly relies on refresh-on-action via add/remove
+// (Logs are NOT polled -- they stream live via Server-Sent Events from /api/logs/stream.)
+setInterval(tickStatus,    3000);
+setInterval(tickPlayers,  10000);
+setInterval(tickWhitelist, 30000);

server/wwwroot/index.html

@@ -0,0 +1,379 @@
+<!doctype html>
+<html lang="en">
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width,initial-scale=1" />
+    <title>Brass &amp; Sigil -- Server Panel</title>
+    <link rel="icon" type="image/png" href="/favicon.png" />
+    <link rel="stylesheet" href="/styles.css" />
+</head>
+<body>
+<div class="topbar">
+    <div class="topbar-left">
+        <img class="topbar-icon" src="/favicon.png" alt="" />
+        <h1>BRASS &amp; SIGIL -- SERVER</h1>
+    </div>
+    <div id="statusPill" class="status-pill"><span class="dot"></span><span id="statusText">Connecting…</span></div>
+</div>
+
+<div class="layout">
+    <aside>
+        <div class="card">
+            <h2>Status</h2>
+            <div class="stat-row"><span class="key">PID</span><span id="pid" class="val">--</span></div>
+            <div class="stat-row"><span class="key">Uptime</span><span id="uptime" class="val">--</span></div>
+            <div class="stat-row"><span class="key">Pack</span><span id="packVersion" class="val">--</span></div>
+            <div class="stat-row"><span class="key">Players</span><span id="playerCount" class="val">--</span></div>
+            <div class="stat-row"><span class="key">World</span><span id="worldSize" class="val">--</span></div>
+            <div class="actions" style="margin-top: 14px;">
+                <button id="btnStart" class="ghost-btn">Start</button>
+                <button id="btnStop" class="danger">Stop</button>
+            </div>
+        </div>
+
+        <div class="card">
+            <h2>Resources</h2>
+            <div class="res-block">
+                <div class="res-label"><span>Memory</span><span id="memUsage" class="res-val">--</span></div>
+                <div class="res-bar"><div id="memBar"></div></div>
+            </div>
+            <div class="res-block">
+                <div class="res-label"><span>CPU</span><span id="cpuCurrent" class="res-val">--</span></div>
+                <div class="res-bar"><div id="cpuBar"></div></div>
+                <div class="res-sub">
+                    <span>Peak (60s) <strong id="cpuMax">--</strong></span>
+                    <span>Avg (60s) <strong id="cpuAvg">--</strong></span>
+                </div>
+            </div>
+        </div>
+
+        <div class="card">
+            <h2>Players online</h2>
+            <ul id="players" class="name-list">
+                <li class="empty-state">No-one online</li>
+            </ul>
+        </div>
+
+        <div class="card">
+            <h2>Whitelist <span id="wlReqBadge" class="badge" hidden></span></h2>
+            <div id="wlRequestsBlock" hidden>
+                <div class="wl-req-label">Pending requests</div>
+                <ul id="wlRequests" class="name-list"></ul>
+            </div>
+            <ul id="whitelist" class="name-list">
+                <li class="empty-state">No players whitelisted yet</li>
+            </ul>
+            <div class="input-row" style="margin-top: 8px;">
+                <div class="input-wrap">
+                    <input id="wlInput" type="text" placeholder="Add player by username…" autocomplete="off" maxlength="16" />
+                </div>
+                <button id="wlAdd">Add</button>
+            </div>
+        </div>
+    </aside>
+
+    <main>
+        <div class="card">
+            <h2>Console</h2>
+            <div id="console" class="console-pane">Connecting to server log…</div>
+            <div class="input-row">
+                <div class="input-wrap">
+                    <div id="cmdGhost" class="ghost"></div>
+                    <input id="cmdInput" type="text"
+                           placeholder="Type a server command (e.g. say hello, op alice, whitelist add bob)…"
+                           autocomplete="off" />
+                    <div id="cmdSuggest" class="suggest-list"></div>
+                </div>
+                <button id="cmdSend">Send</button>
+            </div>
+            <div id="cmdHint" class="hint">
+                <kbd>Tab</kbd> autocomplete · <kbd>↑</kbd>/<kbd>↓</kbd> history · <kbd>Esc</kbd> dismiss
+            </div>
+        </div>
+    </main>
+
+    <aside class="aside-right">
+        <div class="card">
+            <h2>Account</h2>
+            <div class="actions">
+                <button id="acctChangePw" class="ghost-btn">Change password</button>
+                <button id="acctLogout" class="ghost-btn">Log out</button>
+            </div>
+            <div id="acctChangeForm" class="acct-form" hidden>
+                <div class="input-wrap" style="margin-top: 10px;">
+                    <input id="acctCurrent" type="password" placeholder="Current password" autocomplete="current-password" />
+                </div>
+                <div class="input-wrap" style="margin-top: 8px;">
+                    <input id="acctNew" type="password" placeholder="New password (min 8)" autocomplete="new-password" />
+                </div>
+                <div class="input-wrap" style="margin-top: 8px;">
+                    <input id="acctConfirm" type="password" placeholder="Confirm new password" autocomplete="new-password" />
+                </div>
+                <div class="actions" style="margin-top: 10px;">
+                    <button id="acctSubmit">Update</button>
+                    <button id="acctCancel" class="ghost-btn">Cancel</button>
+                </div>
+                <div id="acctMsg" class="acct-msg"></div>
+            </div>
+        </div>
+
+        <div class="card" id="updateCard" hidden>
+            <h2>Modpack update</h2>
+            <div id="updateInfo" class="update-info">
+                <div class="stat-row"><span class="key">Current</span><span id="updCurrent" class="val">--</span></div>
+                <div class="stat-row"><span class="key">Available</span><span id="updAvailable" class="val">--</span></div>
+            </div>
+            <p class="update-note">Updating restarts Minecraft. Players see a countdown banner then the server stops, syncs new mods, and starts again.</p>
+            <div class="input-row" style="margin-top: 8px;">
+                <div class="input-wrap">
+                    <input id="updDelay" type="number" min="0" max="3600" step="30" value="300" placeholder="Warning seconds" />
+                </div>
+                <button id="updStart">Update</button>
+            </div>
+            <div id="updProgress" class="update-progress" hidden>
+                <div id="updPhaseLabel" class="update-phase">Idle</div>
+                <div class="pg-progress-bar"><div id="updProgressFill"></div></div>
+                <div id="updStatusText" class="update-status">--</div>
+                <button id="updCancel" class="ghost-btn" hidden>Cancel countdown</button>
+            </div>
+        </div>
+
+        <div class="card">
+            <h2>Server settings</h2>
+            <div class="stat-row"><span class="key">MOTD</span><span id="ssMotd" class="val">--</span></div>
+            <div class="stat-row"><span class="key">Difficulty</span><span id="ssDifficulty" class="val">--</span></div>
+            <div class="stat-row"><span class="key">View / Sim</span><span id="ssDistances" class="val">--</span></div>
+            <div class="stat-row"><span class="key">Max players</span><span id="ssMaxPlayers" class="val">--</span></div>
+            <div class="stat-row"><span class="key">Whitelist</span><span id="ssWhitelist" class="val">--</span></div>
+            <button class="ghost-btn" style="width: 100%; margin-top: 10px;" data-open-modal="modalSettings">Edit settings</button>
+        </div>
+
+        <div class="card">
+            <h2>World</h2>
+            <div class="trigger-list">
+                <button class="ghost-btn" data-open-modal="modalPregen">
+                    <span>Pre-generate</span>
+                    <span id="pgBadge" class="badge" hidden></span>
+                </button>
+                <button class="ghost-btn" data-open-modal="modalBackup">
+                    <span>Backups</span>
+                    <span id="bkpBadge" class="badge"></span>
+                </button>
+                <button class="ghost-btn" data-open-modal="modalMap">
+                    <span>Map</span>
+                    <span id="mapBadge" class="badge" hidden></span>
+                </button>
+                <button class="ghost-btn" data-open-modal="modalWipe">
+                    <span>Wipe world</span>
+                    <span class="badge" style="color: var(--danger); border-color: #6a2814;">danger</span>
+                </button>
+            </div>
+        </div>
+    </aside>
+</div>
+
+<!-- ── Modals ─────────────────────────────────────────────────────── -->
+
+<div class="modal" id="modalPregen" hidden>
+    <div class="modal-backdrop"></div>
+    <div class="modal-dialog">
+        <div class="modal-header">
+            <h2>Pre-generate world</h2>
+            <button class="modal-close" aria-label="Close">×</button>
+        </div>
+        <p style="font-size: 12px; color: var(--text-muted); margin: 0 0 12px; line-height: 1.45;">
+            Smooths Distant Horizons by generating chunks ahead of time.
+            Run once after first start; takes a while (be patient -- server keeps running).
+        </p>
+        <div class="input-row" style="margin-top: 4px;">
+            <div class="input-wrap">
+                <input id="pgRadius" type="number" min="100" max="20000" step="100" value="1000" placeholder="Radius (blocks)" />
+            </div>
+            <button id="pgStart">Start</button>
+        </div>
+        <div class="actions" style="margin-top: 8px;">
+            <button id="pgPause" class="ghost-btn">Pause</button>
+            <button id="pgContinue" class="ghost-btn">Resume</button>
+            <button id="pgCancel" class="danger">Cancel</button>
+        </div>
+        <div class="pg-status">
+            <div class="stat-row"><span class="key">State</span><span id="pgState" class="val">Idle</span></div>
+            <div class="pg-progress-bar"><div id="pgProgressFill"></div></div>
+            <div class="stat-row"><span class="key">Progress</span><span id="pgProgressText" class="val">--</span></div>
+            <div class="stat-row"><span class="key">Chunks</span><span id="pgChunks" class="val">--</span></div>
+            <div class="stat-row"><span class="key">Rate</span><span id="pgRate" class="val">--</span></div>
+            <div class="stat-row"><span class="key">ETA</span><span id="pgEta" class="val">--</span></div>
+        </div>
+    </div>
+</div>
+
+<div class="modal" id="modalBackup" hidden>
+    <div class="modal-backdrop"></div>
+    <div class="modal-dialog">
+        <div class="modal-header">
+            <h2>Backups</h2>
+            <button class="modal-close" aria-label="Close">×</button>
+        </div>
+        <div class="stat-row" style="font-size: 11px;">
+            <span class="key">Stored at</span><span id="backupDir" class="val" style="font-size: 11px;">--</span>
+        </div>
+        <div class="stat-row" style="font-size: 11px;">
+            <span class="key">Schedule</span><span id="backupSchedule" class="val" style="font-size: 11px;">--</span>
+        </div>
+        <div class="stat-row" style="font-size: 11px;">
+            <span class="key">Next run</span><span id="backupNext" class="val" style="font-size: 11px;">--</span>
+        </div>
+        <div class="stat-row" style="font-size: 11px;">
+            <span class="key">Keep</span><span id="backupKeep" class="val" style="font-size: 11px;">--</span>
+        </div>
+        <div class="actions" style="margin-top: 12px;">
+            <button id="bkpEditSchedule" class="ghost-btn" style="flex: 1;">Edit schedule</button>
+            <button id="bkpCreate">Create now</button>
+        </div>
+        <div id="bkpScheduleForm" class="acct-form" hidden style="margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--card-edge);">
+            <div class="input-row">
+                <div class="input-wrap" style="flex: 1;">
+                    <input id="bkpScheduleInput" type="text" placeholder="04:00  |  04:00,16:00  |  every 6h  |  every 30m" />
+                </div>
+                <div class="input-wrap" style="width: 80px; flex: 0 0 80px;">
+                    <input id="bkpKeepInput" type="number" min="1" max="365" placeholder="Keep" />
+                </div>
+            </div>
+            <p style="font-size: 11px; color: var(--text-muted); margin: 8px 0 0; line-height: 1.45;">
+                Hourly = ~24 backups/day. Each backup pauses world saves for a few seconds.
+                For hourly retention, raise <em>keep</em> to 48+. Empty schedule disables auto-backups.
+            </p>
+            <div class="actions" style="margin-top: 8px;">
+                <button id="bkpScheduleSave">Save</button>
+                <button id="bkpScheduleCancel" class="ghost-btn">Cancel</button>
+            </div>
+        </div>
+        <ul id="bkpList" class="name-list" style="margin-top: 12px;">
+            <li class="empty-state">No backups yet</li>
+        </ul>
+        <div id="bkpMsg" class="acct-msg"></div>
+    </div>
+</div>
+
+<div class="modal" id="modalSettings" hidden>
+    <div class="modal-backdrop"></div>
+    <div class="modal-dialog" style="max-width: 560px;">
+        <div class="modal-header">
+            <h2>Server settings</h2>
+            <button class="modal-close" aria-label="Close">×</button>
+        </div>
+        <p style="font-size: 12px; color: var(--text-muted); margin: 0 0 14px;">
+            These map to <code>server.properties</code>. MC reads them at startup, so changes need a server restart to take effect.
+        </p>
+        <div class="settings-grid">
+            <label>MOTD<input id="ssfMotd" type="text" /></label>
+            <label>Gamemode<select id="ssfGamemode">
+                <option>survival</option><option>creative</option><option>adventure</option><option>spectator</option>
+            </select></label>
+            <label>Difficulty<select id="ssfDifficulty">
+                <option>peaceful</option><option>easy</option><option>normal</option><option>hard</option>
+            </select></label>
+            <label>View distance<input id="ssfViewDistance" type="number" min="3" max="32" step="1" /></label>
+            <label>Sim distance<input id="ssfSimulationDistance" type="number" min="3" max="32" step="1" /></label>
+            <label>Max players<input id="ssfMaxPlayers" type="number" min="1" max="200" step="1" /></label>
+            <label>Spawn protection<input id="ssfSpawnProtection" type="number" min="0" max="64" step="1" /></label>
+        </div>
+        <div class="settings-checks">
+            <label class="danger-row"><input id="ssfPvp" type="checkbox" /><span>PvP</span></label>
+            <label class="danger-row"><input id="ssfHardcore" type="checkbox" /><span>Hardcore</span></label>
+            <label class="danger-row"><input id="ssfAllowFlight" type="checkbox" /><span>Allow flight</span></label>
+            <label class="danger-row"><input id="ssfWhiteList" type="checkbox" /><span>Whitelist enabled</span></label>
+            <label class="danger-row"><input id="ssfEnforceWhitelist" type="checkbox" /><span>Enforce whitelist</span></label>
+            <label class="danger-row"><input id="ssfEnableCommandBlock" type="checkbox" /><span>Enable command blocks</span></label>
+        </div>
+        <div class="actions" style="margin-top: 14px;">
+            <button id="ssSave" style="flex: 1;">Save</button>
+            <button id="ssRestart" class="ghost-btn">Save &amp; restart</button>
+        </div>
+        <div id="ssMsg" class="acct-msg"></div>
+    </div>
+</div>
+
+<div class="modal" id="modalMap" hidden>
+    <div class="modal-backdrop"></div>
+    <div class="modal-dialog">
+        <div class="modal-header">
+            <h2>World map</h2>
+            <button class="modal-close" aria-label="Close">×</button>
+        </div>
+        <p style="font-size: 12px; color: var(--text-muted); margin: 0 0 14px; line-height: 1.45;">
+            Renders the world to a browsable 3D map (BlueMap). Runs as a separate process -- no impact on the live MC server.
+            First render of a 5000-block area takes 2-6 hours; subsequent renders are incremental and much faster.
+        </p>
+        <div class="stat-row"><span class="key">Phase</span><span id="mapPhase" class="val">Idle</span></div>
+        <div class="stat-row"><span class="key">Last log</span><span id="mapLastLog" class="val" style="font-size: 10px; max-width: 300px; overflow: hidden; text-overflow: ellipsis;">--</span></div>
+        <div class="actions" style="margin-top: 14px;">
+            <button id="mapRender" style="flex: 1;">Render now</button>
+            <button id="mapCancel" class="danger" hidden>Cancel</button>
+            <button id="mapOpen" class="ghost-btn">Open map ↗</button>
+        </div>
+        <div id="mapMsg" class="acct-msg"></div>
+    </div>
+</div>
+
+<div class="modal" id="modalWipe" hidden>
+    <div class="modal-backdrop"></div>
+    <div class="modal-dialog danger">
+        <div class="modal-header">
+            <h2>Wipe world</h2>
+            <button class="modal-close" aria-label="Close">×</button>
+        </div>
+        <p class="danger-note">
+            Wipes the world directory and restarts the server with a fresh world.
+            With "Back up first" ticked, the old world is archived to your backup directory before deletion.
+            Players see a 30-second urgent warning before the wipe begins.
+        </p>
+        <label class="danger-row">
+            <input id="wipeBackup" type="checkbox" checked />
+            <span>Back up current world before wiping</span>
+        </label>
+
+        <div class="danger-section">
+            <div class="danger-section-title">World seed</div>
+            <div class="danger-row" style="margin-bottom: 6px;">
+                <span>Current:</span>
+                <code id="wipeCurrentSeed" style="margin-left: 8px;">loading...</code>
+            </div>
+            <label class="danger-row">
+                <input type="radio" name="wipeSeedMode" value="random" checked />
+                <span>Random new seed (Minecraft picks one)</span>
+            </label>
+            <label class="danger-row">
+                <input type="radio" name="wipeSeedMode" value="keep" />
+                <span>Keep current seed (regenerate identical world)</span>
+            </label>
+            <label class="danger-row">
+                <input type="radio" name="wipeSeedMode" value="custom" />
+                <span>Custom seed:</span>
+                <input id="wipeCustomSeed" type="text" placeholder="e.g. 12345 or 'a phrase'"
+                       style="margin-left: 8px; flex: 1;" disabled />
+            </label>
+        </div>
+
+        <button id="wipeBtn" class="danger" style="margin-top: 14px; width: 100%;">Wipe world</button>
+        <div id="wipeMsg" class="acct-msg"></div>
+    </div>
+</div>
+
+<div class="footer">brass-sigil-server v0.1 -- embedded panel</div>
+
+<div id="loginOverlay" class="login-overlay" hidden>
+    <div class="login-box">
+        <h2>Brass &amp; Sigil</h2>
+        <p>Sign in to manage the server.</p>
+        <div class="input-wrap">
+            <input id="loginPassword" type="password" autocomplete="current-password" placeholder="Password" />
+        </div>
+        <button id="loginSubmit">Sign in</button>
+        <div id="loginError" class="login-error"></div>
+    </div>
+</div>
+
+<script type="module" src="/app.js"></script>
+</body>
+</html>

server/wwwroot/modules/api.js

@@ -0,0 +1,28 @@
+// Tiny JSON API helper used by every module.
+"use strict";
+
+export async function api(path, opts) {
+    const res = await fetch(path, opts);
+    if (res.status === 401) {
+        // Auth cookie missing or wrong. Surface to the auth module which
+        // shows the login overlay; the caller still gets an error so any
+        // calling code stops cleanly.
+        document.dispatchEvent(new CustomEvent("authrequired"));
+        throw new Error("Unauthorized");
+    }
+    if (!res.ok) throw new Error(`${path} → HTTP ${res.status}`);
+    return await res.json();
+}
+
+export async function apiJson(path, body, method = "POST") {
+    return api(path, {
+        method,
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(body)
+    });
+}
+
+export function escapeHtml(s) {
+    return s.replace(/[&<>"']/g, c =>
+        ({"&":"&amp;","<":"&lt;",">":"&gt;",'"':"&quot;","'":"&#39;"}[c]));
+}

server/wwwroot/modules/auth.js

@@ -0,0 +1,115 @@
+// Login overlay + Account panel (logout / change password).
+//
+// Cookie is set server-side as HttpOnly so JS never sees it -- that defeats
+// XSS-based exfiltration. We only briefly hold the password during input.
+"use strict";
+
+// We deliberately don't import apiJson here -- change-password returns its
+// own error messages and we want to surface them verbatim to the user.
+
+let overlayShown = false;
+function showOverlay() {
+    if (overlayShown) return;
+    overlayShown = true;
+    const overlay = document.getElementById("loginOverlay");
+    if (overlay) {
+        overlay.hidden = false;
+        document.getElementById("loginPassword")?.focus();
+    }
+}
+
+export function setupAuth() {
+    document.addEventListener("authrequired", showOverlay);
+    setupLoginForm();
+    setupAccountPanel();
+}
+
+function setupLoginForm() {
+    const overlay = document.getElementById("loginOverlay");
+    const input   = document.getElementById("loginPassword");
+    const button  = document.getElementById("loginSubmit");
+    const errorEl = document.getElementById("loginError");
+    if (!overlay || !input || !button || !errorEl) return;
+
+    async function tryLogin() {
+        const pw = input.value;
+        if (!pw) return;
+        errorEl.textContent = "";
+        button.disabled = true;
+        try {
+            const res = await fetch("/api/auth/login", {
+                method:  "POST",
+                headers: { "Content-Type": "application/json" },
+                body:    JSON.stringify({ password: pw }),
+            });
+            if (res.status === 401) { errorEl.textContent = "Wrong password."; input.select(); return; }
+            if (res.status === 429) { errorEl.textContent = "Too many attempts. Wait a minute."; return; }
+            if (!res.ok)            { errorEl.textContent = `Error ${res.status}`; return; }
+            // Server set the cookie. Reload so SSE / pollers pick it up.
+            location.reload();
+        } catch (e) {
+            errorEl.textContent = e.message;
+        } finally {
+            button.disabled = false;
+            input.value = "";
+        }
+    }
+
+    button.addEventListener("click", tryLogin);
+    input.addEventListener("keydown", e => { if (e.key === "Enter") tryLogin(); });
+}
+
+function setupAccountPanel() {
+    const logoutBtn = document.getElementById("acctLogout");
+    const changeBtn = document.getElementById("acctChangePw");
+    const form      = document.getElementById("acctChangeForm");
+    const cur       = document.getElementById("acctCurrent");
+    const nxt       = document.getElementById("acctNew");
+    const cnf       = document.getElementById("acctConfirm");
+    const submit    = document.getElementById("acctSubmit");
+    const cancel    = document.getElementById("acctCancel");
+    const msg       = document.getElementById("acctMsg");
+    if (!logoutBtn || !changeBtn) return;
+
+    logoutBtn.addEventListener("click", async () => {
+        if (!confirm("Log out of the panel?")) return;
+        try { await fetch("/api/auth/logout", { method: "POST" }); }
+        finally { location.reload(); }
+    });
+
+    changeBtn.addEventListener("click", () => {
+        form.hidden = !form.hidden;
+        msg.textContent = "";
+        if (!form.hidden) cur.focus();
+    });
+    cancel.addEventListener("click", () => {
+        form.hidden = true;
+        cur.value = nxt.value = cnf.value = "";
+        msg.textContent = "";
+    });
+
+    submit.addEventListener("click", async () => {
+        msg.className = "acct-msg";
+        msg.textContent = "";
+        if (nxt.value.length < 8) { msg.textContent = "New password must be at least 8 characters."; return; }
+        if (nxt.value !== cnf.value) { msg.textContent = "New password and confirmation don't match."; return; }
+        submit.disabled = true;
+        try {
+            const res = await fetch("/api/auth/change-password", {
+                method:  "POST",
+                headers: { "Content-Type": "application/json" },
+                body:    JSON.stringify({ current: cur.value, next: nxt.value }),
+            });
+            const body = await res.json().catch(() => ({}));
+            if (!res.ok) { msg.textContent = body.error || `Error ${res.status}`; return; }
+            msg.className = "acct-msg ok";
+            msg.textContent = "Password changed.";
+            cur.value = nxt.value = cnf.value = "";
+            setTimeout(() => { form.hidden = true; msg.textContent = ""; }, 1500);
+        } catch (e) {
+            msg.textContent = e.message;
+        } finally {
+            submit.disabled = false;
+        }
+    });
+}

server/wwwroot/modules/autocomplete.js

@@ -0,0 +1,263 @@
+// Tab-completion + suggestion dropdown for the console command input.
+//   - Ghost text shows the top match inline (Tab to accept)
+//   - A dropdown list shows up to N matches with their argument signature
+//     (MC-style: <required> [optional] <a|b|c> for choices)
+//   - Click a list item to insert it; arrow keys + Enter also navigate the list
+//     when it's open
+"use strict";
+
+import { state } from "./state.js";
+import { escapeHtml } from "./api.js";
+
+const COMMANDS = [
+    "help", "list", "say", "tell", "msg", "me", "w",
+    "op", "deop",
+    "whitelist", "ban", "ban-ip", "pardon", "pardon-ip", "banlist",
+    "kick",
+    "tp", "teleport",
+    "give", "clear", "kill",
+    "gamemode", "gamerule", "difficulty",
+    "weather", "time", "seed", "spawnpoint", "setworldspawn",
+    "save-all", "save-on", "save-off", "stop", "reload",
+    "xp", "experience", "effect", "enchant",
+    "summon", "data", "execute", "fill", "setblock", "locate", "tag",
+    "ftbchunks", "ftbteams",
+    "chunky",
+    "kubejs", "kjs",
+];
+
+const SUBCOMMANDS = {
+    whitelist:  ["add", "remove", "list", "reload", "on", "off"],
+    gamemode:   ["survival", "creative", "adventure", "spectator"],
+    weather:    ["clear", "rain", "thunder"],
+    difficulty: ["peaceful", "easy", "normal", "hard"],
+    time:       ["set", "add", "query"],
+    chunky:     ["start", "cancel", "pause", "continue", "world", "shape", "center", "radius", "force_load", "force_unload", "trim", "help"],
+    ftbchunks:  ["claim", "unclaim", "load", "unload", "admin"],
+};
+
+const TAKES_PLAYER_AT = {
+    "op": 1, "deop": 1, "tp": 1, "teleport": 1, "kick": 1,
+    "ban": 1, "pardon": 1, "kill": 1,
+    "tell": 1, "msg": 1, "w": 1,
+    "give": 1, "clear": 1, "effect": 1, "enchant": 1, "xp": 1, "experience": 1,
+    "whitelist add": 2, "whitelist remove": 2,
+    "gamemode survival": 2, "gamemode creative": 2, "gamemode adventure": 2, "gamemode spectator": 2,
+};
+
+// MC-style argument signatures for each command. Shown as a hint after the name
+// in the suggestion list. <required> [optional] <a|b|c> for enum choices.
+const SIGNATURES = {
+    help:           "[command]",
+    list:           "",
+    say:            "<message>",
+    tell:           "<player> <message>",
+    msg:            "<player> <message>",
+    me:             "<action>",
+    w:              "<player> <message>",
+    op:             "<player>",
+    deop:           "<player>",
+    whitelist:      "<add|remove|list|reload|on|off>",
+    "whitelist add":     "<player>",
+    "whitelist remove":  "<player>",
+    "whitelist list":    "",
+    "whitelist on":      "",
+    "whitelist off":     "",
+    "whitelist reload":  "",
+    ban:            "<player> [reason…]",
+    "ban-ip":       "<ip|player> [reason…]",
+    pardon:         "<player>",
+    "pardon-ip":    "<ip>",
+    banlist:        "[ips|players]",
+    kick:           "<player> [reason…]",
+    tp:             "<target> [destination]",
+    teleport:       "<target> [destination]",
+    give:           "<player> <item> [count]",
+    clear:          "[player] [item]",
+    kill:           "[target]",
+    gamemode:       "<mode> [player]",
+    "gamemode survival":  "[player]",
+    "gamemode creative":  "[player]",
+    "gamemode adventure": "[player]",
+    "gamemode spectator": "[player]",
+    gamerule:       "<rule> [value]",
+    difficulty:     "<peaceful|easy|normal|hard>",
+    weather:        "<clear|rain|thunder> [duration]",
+    time:           "<set|add|query> <value>",
+    seed:           "",
+    spawnpoint:     "[player] [pos]",
+    setworldspawn:  "[pos]",
+    "save-all":     "[flush]",
+    "save-on":      "",
+    "save-off":     "",
+    stop:           "",
+    reload:         "",
+    xp:             "<amount> [player]",
+    experience:     "<add|set|query> <player> <amount>",
+    effect:         "<give|clear> <player> <effect>",
+    enchant:        "<player> <enchantment> [level]",
+    summon:         "<entity> [pos]",
+    fill:           "<from> <to> <block>",
+    setblock:       "<pos> <block>",
+    locate:         "<biome|structure> <id>",
+    tag:            "<target> <add|remove|list> [tag]",
+    chunky:         "<start|cancel|pause|continue|world|shape|center|radius|trim|...>",
+    "chunky start":    "[world] [shape] [center_x] [center_z] [radius]",
+    "chunky cancel":   "",
+    "chunky pause":    "",
+    "chunky continue": "",
+    "chunky world":    "<world>",
+    "chunky shape":    "<square|circle|...>",
+    "chunky center":   "<x> <z>",
+    "chunky radius":   "<radius>",
+    "chunky trim":     "[world] [radius] [trim_radius]",
+    ftbchunks:      "<claim|unclaim|load|unload|admin>",
+    ftbteams:       "<list|info|invite|...>",
+    kubejs:         "<reload|hand|stages|...>",
+    kjs:            "<reload|hand|stages|...>",
+};
+
+const MAX_SUGGESTIONS = 8;
+
+let activeIndex = 0;
+let currentSuggestions = [];
+
+export function setupAutocomplete() {
+    const cmdInput = document.getElementById("cmdInput");
+    const cmdGhost = document.getElementById("cmdGhost");
+    const cmdSuggest = document.getElementById("cmdSuggest");
+
+    function refresh() {
+        const v = cmdInput.value;
+        currentSuggestions = computeAllSuggestions(v).slice(0, MAX_SUGGESTIONS);
+        activeIndex = 0;
+
+        // Inline ghost = top suggestion (only if it extends what they typed)
+        const top = currentSuggestions[0];
+        if (top && top.text.startsWith(v) && top.text !== v) {
+            const suffix = top.text.substring(v.length);
+            cmdGhost.innerHTML = `<span class="typed">${escapeHtml(v)}</span>${escapeHtml(suffix)}`;
+            cmdInput.dataset.suggestion = top.text;
+        } else {
+            cmdGhost.innerHTML = "";
+            cmdInput.dataset.suggestion = "";
+        }
+
+        renderList(cmdSuggest, currentSuggestions);
+    }
+
+    cmdInput.addEventListener("input", refresh);
+    cmdInput.addEventListener("focus", refresh);
+    cmdInput.addEventListener("blur", () => {
+        // Delay so a click on a list item registers before we hide
+        setTimeout(() => cmdSuggest.classList.remove("show"), 150);
+    });
+
+    cmdInput.addEventListener("keydown", e => {
+        if (e.key === "Tab") {
+            const sug = currentSuggestions[activeIndex];
+            if (sug) {
+                e.preventDefault();
+                cmdInput.value = sug.text + " ";
+                refresh();
+            }
+        } else if (e.key === "Escape") {
+            cmdGhost.innerHTML = "";
+            cmdInput.dataset.suggestion = "";
+            cmdSuggest.classList.remove("show");
+        } else if (e.key === "ArrowDown" && cmdSuggest.classList.contains("show") && currentSuggestions.length > 0) {
+            e.preventDefault();
+            activeIndex = (activeIndex + 1) % currentSuggestions.length;
+            highlightActive(cmdSuggest);
+        } else if (e.key === "ArrowUp" && cmdSuggest.classList.contains("show") && currentSuggestions.length > 0) {
+            e.preventDefault();
+            activeIndex = (activeIndex - 1 + currentSuggestions.length) % currentSuggestions.length;
+            highlightActive(cmdSuggest);
+        }
+        // Note: Enter is handled by console.js (sends the command)
+    });
+
+    cmdSuggest.addEventListener("mousedown", e => {
+        // mousedown (not click) so we beat the input blur handler
+        const item = e.target.closest(".suggest-item");
+        if (!item) return;
+        e.preventDefault();
+        const idx = parseInt(item.dataset.idx, 10);
+        const sug = currentSuggestions[idx];
+        if (sug) {
+            cmdInput.value = sug.text + " ";
+            cmdInput.focus();
+            refresh();
+        }
+    });
+}
+
+function highlightActive(listEl) {
+    [...listEl.querySelectorAll(".suggest-item")].forEach((el, i) => {
+        el.classList.toggle("active", i === activeIndex);
+        if (i === activeIndex) el.scrollIntoView({ block: "nearest" });
+    });
+}
+
+function renderList(listEl, suggestions) {
+    if (suggestions.length === 0) {
+        listEl.classList.remove("show");
+        listEl.innerHTML = "";
+        return;
+    }
+    listEl.innerHTML = suggestions.map((s, i) => {
+        const args = s.args ? `<span class="args">${escapeHtml(s.args)}</span>` : "";
+        return `<div class="suggest-item${i === activeIndex ? " active" : ""}" data-idx="${i}">` +
+               `<span>${escapeHtml(s.text)}</span>${args}</div>`;
+    }).join("");
+    listEl.classList.add("show");
+}
+
+// Returns an array of {text, args} suggestions ordered by relevance.
+// args is the MC-style hint shown next to the name.
+function computeAllSuggestions(input) {
+    if (!input) return [];
+    const stripped = input.startsWith("/") ? input.substring(1) : input;
+    const tokens = stripped.split(" ");
+    const partial = tokens[tokens.length - 1].toLowerCase();
+    const completed = tokens.slice(0, -1);
+    const prefix = input.startsWith("/") ? "/" : "";
+
+    // First token: command name
+    if (completed.length === 0) {
+        const matches = COMMANDS.filter(c => c.startsWith(partial)).sort();
+        return matches.map(name => ({
+            text: prefix + name,
+            args: SIGNATURES[name] ?? "",
+        }));
+    }
+
+    // Subcommands
+    const headLower = completed[0].toLowerCase();
+    if (completed.length === 1 && SUBCOMMANDS[headLower]) {
+        const subs = SUBCOMMANDS[headLower].filter(s => s.startsWith(partial));
+        return subs.map(sub => ({
+            text: prefix + [...completed, sub].join(" "),
+            args: SIGNATURES[`${headLower} ${sub}`] ?? "",
+        }));
+    }
+
+    // Player-name positions
+    const cmdKey = completed.join(" ").toLowerCase();
+    const playerSlot = TAKES_PLAYER_AT[cmdKey];
+    if (playerSlot !== undefined && tokens.length === playerSlot + 1) {
+        const matches = state.knownPlayers.filter(p => p.toLowerCase().startsWith(partial));
+        return matches.map(p => ({
+            text: prefix + [...completed, p].join(" "),
+            args: "",
+        }));
+    }
+
+    // No structured suggestion at this position -- but still show the current
+    // command's signature as a contextual hint
+    const sig = SIGNATURES[cmdKey];
+    if (sig) {
+        return [{ text: input, args: sig }];
+    }
+    return [];
+}

server/wwwroot/modules/backup.js

@@ -0,0 +1,183 @@
+// World backup management -- list, create, restore, delete.
+//
+// Backups are server-online (no downtime) -- the daemon issues `save-all flush`
+// + `save-off`, archives the world, then `save-on`. Restore *does* stop the
+// server (it has to), and snapshots the current world to a `-prerestore-*` dir
+// before extracting so a wrong restore is recoverable.
+"use strict";
+
+import { api } from "./api.js";
+
+const els = {};
+let lastSchedule = null;
+let lastKeep = null;
+
+function fmtSize(bytes) {
+    if (bytes < 1024) return `${bytes} B`;
+    if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(0)} KB`;
+    if (bytes < 1024 * 1024 * 1024) return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
+    return `${(bytes / (1024 * 1024 * 1024)).toFixed(2)} GB`;
+}
+
+function fmtDate(iso) {
+    try { return new Date(iso).toLocaleString(); } catch { return iso; }
+}
+
+function fmtRelativeFuture(iso) {
+    if (!iso) return "--";
+    const target = new Date(iso).getTime();
+    const ms = target - Date.now();
+    if (ms <= 0) return "imminent";
+    const sec = Math.round(ms / 1000);
+    if (sec < 60)   return `in ${sec}s`;
+    const min = Math.round(sec / 60);
+    if (min < 60)   return `in ${min}m`;
+    const hr  = Math.floor(min / 60);
+    const rem = min % 60;
+    if (hr < 24)    return rem ? `in ${hr}h ${rem}m` : `in ${hr}h`;
+    const days = Math.floor(hr / 24);
+    return `in ${days}d ${hr % 24}h`;
+}
+
+async function refresh() {
+    let data;
+    try { data = await api("/api/backup/list"); }
+    catch { return; }
+
+    els.dir.textContent      = data.dir || "--";
+    // Server returns a human description ("Daily at 04:00", "Every 6 hours", "Disabled").
+    els.schedule.textContent = data.description || (data.schedule ? `Daily at ${data.schedule}` : "Disabled");
+    els.next.textContent     = data.nextRun ? fmtRelativeFuture(data.nextRun) : "--";
+    els.keep.textContent     = data.keep != null ? `${data.keep} latest` : "--";
+    lastSchedule = data.schedule || "";
+    lastKeep = data.keep ?? 14;
+
+    // Right-sidebar badge: count of backups
+    const badge = document.getElementById("bkpBadge");
+    if (badge) badge.textContent = data.backups?.length ? `${data.backups.length}` : "0";
+
+    if (!data.backups || data.backups.length === 0) {
+        els.list.innerHTML = '<li class="empty-state">No backups yet</li>';
+        return;
+    }
+
+    els.list.innerHTML = data.backups.map(b => `
+        <li class="backup-item">
+            <div class="backup-meta">
+                <div class="backup-name">${escape(b.name)}</div>
+                <div class="backup-sub">${fmtSize(b.sizeBytes)} · ${fmtDate(b.createdAt)}</div>
+            </div>
+            <div class="backup-actions">
+                <button class="ghost-btn bkp-restore" data-name="${escape(b.name)}">Restore</button>
+                <button class="ghost-btn bkp-delete"  data-name="${escape(b.name)}">Delete</button>
+            </div>
+        </li>
+    `).join("");
+}
+
+function escape(s) {
+    return String(s).replace(/[&<>"']/g, c =>
+        ({"&":"&amp;","<":"&lt;",">":"&gt;",'"':"&quot;","'":"&#39;"}[c]));
+}
+
+function showMsg(text, ok = false) {
+    els.msg.className = ok ? "acct-msg ok" : "acct-msg";
+    els.msg.textContent = text;
+}
+
+async function postJson(path, body) {
+    const res = await fetch(path, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(body),
+    });
+    return { ok: res.ok, status: res.status, body: await res.json().catch(() => ({})) };
+}
+
+export function setupBackup() {
+    els.dir       = document.getElementById("backupDir");
+    els.list      = document.getElementById("bkpList");
+    els.create    = document.getElementById("bkpCreate");
+    els.msg       = document.getElementById("bkpMsg");
+    els.schedule  = document.getElementById("backupSchedule");
+    els.next      = document.getElementById("backupNext");
+    els.keep      = document.getElementById("backupKeep");
+    els.editBtn   = document.getElementById("bkpEditSchedule");
+    els.form      = document.getElementById("bkpScheduleForm");
+    els.input     = document.getElementById("bkpScheduleInput");
+    els.keepInput = document.getElementById("bkpKeepInput");
+    els.saveBtn   = document.getElementById("bkpScheduleSave");
+    els.cancelBtn = document.getElementById("bkpScheduleCancel");
+    if (!els.create) return;
+
+    els.editBtn?.addEventListener("click", () => {
+        els.form.hidden = !els.form.hidden;
+        if (!els.form.hidden) {
+            els.input.value     = lastSchedule || "";
+            els.keepInput.value = lastKeep ?? 14;
+            els.input.focus();
+        }
+    });
+
+    els.cancelBtn?.addEventListener("click", () => {
+        els.form.hidden = true;
+        showMsg("");
+    });
+
+    els.saveBtn?.addEventListener("click", async () => {
+        const sched = els.input.value.trim();
+        const keep  = parseInt(els.keepInput.value, 10);
+        const r = await postJson("/api/backup/schedule", {
+            schedule: sched,
+            keep:     Number.isFinite(keep) ? keep : undefined,
+        });
+        if (!r.ok || r.body.ok === false) {
+            showMsg(r.body.error || `Error ${r.status}`);
+        } else {
+            showMsg(sched ? `Schedule saved: daily at ${sched}` : "Schedule disabled.", true);
+            els.form.hidden = true;
+            refresh();
+        }
+    });
+
+    els.create.addEventListener("click", async () => {
+        const reason = prompt("Optional reason / label for this backup (e.g. 'pre-update'). Leave blank for none:");
+        if (reason === null) return; // user cancelled
+        showMsg("Creating backup -- this may take a minute on a large world...");
+        els.create.disabled = true;
+        const r = await postJson("/api/backup/create", { reason: reason.trim() || null });
+        els.create.disabled = false;
+        if (!r.ok || r.body.ok === false) {
+            showMsg(r.body.error || `Error ${r.status}`);
+        } else {
+            showMsg(`Backup created: ${r.body.name} (${fmtSize(r.body.sizeBytes)})`, true);
+            refresh();
+        }
+    });
+
+    els.list.addEventListener("click", async e => {
+        const restore = e.target.closest(".bkp-restore");
+        const del     = e.target.closest(".bkp-delete");
+        if (restore) {
+            const name = restore.dataset.name;
+            if (!confirm(`Restore from ${name}?\n\nServer will stop, current world is moved to a "-prerestore" folder for safety, then the backup is extracted and server starts again.`))
+                return;
+            showMsg("Restoring -- this stops the server...");
+            const r = await postJson("/api/backup/restore", { name });
+            if (!r.ok || r.body.ok === false) showMsg(r.body.error || `Error ${r.status}`);
+            else showMsg("Restore complete. Server is starting.", true);
+        }
+        if (del) {
+            const name = del.dataset.name;
+            if (!confirm(`Delete backup ${name}? This cannot be undone.`)) return;
+            const r = await postJson("/api/backup/delete", { name });
+            if (!r.ok || r.body.ok === false) showMsg(r.body.error || `Error ${r.status}`);
+            else { showMsg("Deleted.", true); refresh(); }
+        }
+    });
+
+    refresh();
+    // Backups don't change often; light poll to pick up new ones if scheduled
+    // backups are added later, or just to refresh after an external mv/rm.
+    setInterval(refresh, 30000);
+}

server/wwwroot/modules/console.js

@@ -0,0 +1,76 @@
+// Live log streaming via Server-Sent Events + command-input wiring.
+// EventSource gives us instant push (no 1-second polling lag) and reconnects
+// automatically if the connection drops.
+"use strict";
+
+import { api, apiJson, escapeHtml } from "./api.js";
+import { state } from "./state.js";
+
+const consoleEl = () => document.getElementById("console");
+
+export function setupConsole() {
+    consoleEl().textContent = "Connecting to server log…";
+
+    const es = new EventSource("/api/logs/stream");
+    let firstEvent = true;
+    es.addEventListener("log", e => {
+        if (firstEvent) { consoleEl().textContent = ""; firstEvent = false; }
+        try {
+            const d = JSON.parse(e.data);
+            const ts = new Date(d.t).toLocaleTimeString();
+            const div = document.createElement("div");
+            if (d.e) div.className = "err";
+            div.textContent = `[${ts}] ${d.m}`;
+            consoleEl().appendChild(div);
+            consoleEl().scrollTop = consoleEl().scrollHeight;
+            // Trim very old lines so the DOM doesn't grow unbounded
+            while (consoleEl().childNodes.length > 5000) {
+                consoleEl().removeChild(consoleEl().firstChild);
+            }
+            // Re-broadcast so other modules (e.g. pregen) can react to log lines
+            // without opening a second SSE connection.
+            document.dispatchEvent(new CustomEvent("serverlog", { detail: d }));
+        } catch {}
+    });
+    es.onerror = () => {
+        // EventSource will retry automatically.
+    };
+
+    // Command input
+    const cmdInput = document.getElementById("cmdInput");
+    document.getElementById("cmdSend").addEventListener("click", sendCommand);
+    cmdInput.addEventListener("keydown", onCmdKeyDown);
+}
+
+async function sendCommand() {
+    const cmdInput = document.getElementById("cmdInput");
+    const v = cmdInput.value.trim();
+    if (!v) return;
+    try {
+        await apiJson("/api/command", { command: v });
+        state.cmdHistory.push(v);
+        state.cmdHistoryIdx = state.cmdHistory.length;
+        cmdInput.value = "";
+        cmdInput.dispatchEvent(new Event("input")); // refresh ghost text
+    } catch (e) { alert(e.message); }
+}
+
+function onCmdKeyDown(e) {
+    const cmdInput = document.getElementById("cmdInput");
+    if (e.key === "Enter") {
+        sendCommand();
+    } else if (e.key === "ArrowUp") {
+        if (state.cmdHistory.length === 0) return;
+        e.preventDefault();
+        state.cmdHistoryIdx = Math.max(0, state.cmdHistoryIdx - 1);
+        cmdInput.value = state.cmdHistory[state.cmdHistoryIdx] || "";
+        cmdInput.dispatchEvent(new Event("input"));
+    } else if (e.key === "ArrowDown") {
+        if (state.cmdHistory.length === 0) return;
+        e.preventDefault();
+        state.cmdHistoryIdx = Math.min(state.cmdHistory.length, state.cmdHistoryIdx + 1);
+        cmdInput.value = state.cmdHistory[state.cmdHistoryIdx] || "";
+        cmdInput.dispatchEvent(new Event("input"));
+    }
+    // Note: Tab is handled by the autocomplete module's keydown listener.
+}

server/wwwroot/modules/danger.js

@@ -0,0 +1,111 @@
+// Danger zone -- destructive operations.
+// Currently: world wipe. Always type-to-confirm to prevent accidental clicks.
+"use strict";
+
+export function setupDanger() {
+    const btn          = document.getElementById("wipeBtn");
+    const cb           = document.getElementById("wipeBackup");
+    const msg          = document.getElementById("wipeMsg");
+    const seedDisplay  = document.getElementById("wipeCurrentSeed");
+    const customInput  = document.getElementById("wipeCustomSeed");
+    if (!btn) return;
+
+    // Enable the custom-seed text field only when its radio is selected.
+    document.querySelectorAll('input[name="wipeSeedMode"]').forEach(radio => {
+        radio.addEventListener("change", () => {
+            const mode = document.querySelector('input[name="wipeSeedMode"]:checked')?.value;
+            customInput.disabled = (mode !== "custom");
+            if (mode === "custom") customInput.focus();
+        });
+    });
+
+    // Fetch current seed each time the wipe modal becomes visible. Watching
+    // the wipe section's ancestor modal works without coupling to the modal
+    // module's open/close API.
+    const refreshSeed = async () => {
+        seedDisplay.textContent = "loading...";
+        try {
+            const res = await fetch("/api/world/seed");
+            const body = await res.json();
+            seedDisplay.textContent = body.seed
+                ? body.seed
+                : "(unknown -- server stopped or seed not set)";
+        } catch (e) {
+            seedDisplay.textContent = "(failed to read)";
+        }
+    };
+    // Refresh on first load + whenever the modal becomes visible. Modal markup
+    // uses a wrapping div with "[hidden]" attr, so we observe attribute changes.
+    refreshSeed();
+    const modal = btn.closest(".modal");
+    if (modal) {
+        new MutationObserver(muts => {
+            for (const m of muts) {
+                if (m.attributeName === "hidden" && !modal.hasAttribute("hidden")) {
+                    refreshSeed();
+                }
+            }
+        }).observe(modal, { attributes: true });
+    }
+
+    btn.addEventListener("click", async () => {
+        msg.className = "acct-msg";
+        msg.textContent = "";
+
+        const mode = document.querySelector('input[name="wipeSeedMode"]:checked')?.value || "random";
+        const customSeed = (customInput.value || "").trim();
+        if (mode === "custom" && !customSeed) {
+            msg.textContent = "Custom seed selected but the field is empty.";
+            return;
+        }
+
+        // Build a confirmation prompt that reflects the chosen seed strategy
+        // so the user sees exactly what's about to happen.
+        let seedNote = "";
+        if      (mode === "keep")   seedNote = `Same seed (${seedDisplay.textContent}) will be reused.\n`;
+        else if (mode === "custom") seedNote = `Seed will be set to: ${customSeed}\n`;
+        else                        seedNote = "A new random seed will be generated.\n";
+
+        const typed = prompt(
+            "Type WIPE (uppercase, exactly) to confirm world wipe.\n" +
+            "Server will stop, world will be replaced, server will restart.\n\n" +
+            seedNote
+        );
+        if (typed !== "WIPE") {
+            if (typed != null) msg.textContent = "Confirmation didn't match -- nothing wiped.";
+            return;
+        }
+
+        btn.disabled = true;
+        msg.textContent = "Wiping...";
+        try {
+            const res = await fetch("/api/world/wipe", {
+                method: "POST",
+                headers: { "Content-Type": "application/json" },
+                body: JSON.stringify({
+                    confirm: typed,
+                    backup: cb.checked,
+                    seedMode: mode,
+                    customSeed: mode === "custom" ? customSeed : null,
+                }),
+            });
+            const body = await res.json().catch(() => ({}));
+            if (!res.ok || body.ok === false) {
+                msg.textContent = body.error || `Error ${res.status}`;
+                return;
+            }
+            msg.className = "acct-msg ok";
+            const parts = ["World wiped."];
+            if (body.seedUsed) parts.push(`Seed: ${body.seedUsed}.`);
+            if (body.backupName) parts.push(`Backup: ${body.backupName}.`);
+            parts.push("Server restarting...");
+            msg.textContent = parts.join(" ");
+            // Refresh the seed display so user sees the new value once MC is back.
+            setTimeout(refreshSeed, 5000);
+        } catch (e) {
+            msg.textContent = e.message;
+        } finally {
+            btn.disabled = false;
+        }
+    });
+}

server/wwwroot/modules/map.js

@@ -0,0 +1,114 @@
+// World map (BlueMap) controls.
+//
+// Render runs out-of-process via BlueMap CLI. Status polled every 3 s while
+// the modal is open OR while a render is in progress. The "Open map" button
+// only opens the new tab if there's actually rendered output -- otherwise we
+// pop a friendly message saying "render first".
+"use strict";
+
+import { api } from "./api.js";
+
+const els = {};
+let pollTimer = null;
+let modalOpen = false;
+let lastHasOutput = false;
+
+function setPolling(intervalMs) {
+    if (pollTimer) clearInterval(pollTimer);
+    pollTimer = setInterval(tick, intervalMs);
+}
+
+async function tick() {
+    let s;
+    try { s = await api("/api/map/status"); }
+    catch { return; }
+
+    lastHasOutput = !!s.hasOutput;
+    document.getElementById("mapBadge").hidden = !s.inProgress;
+    if (s.inProgress) document.getElementById("mapBadge").textContent = "rendering";
+
+    if (!modalOpen) return; // don't bother updating modal DOM if hidden
+
+    els.phase.textContent   = phaseLabel(s.phase);
+    els.lastLog.textContent = s.lastLogLine ?? "--";
+    els.render.disabled = s.inProgress;
+    els.render.textContent = s.inProgress ? "Rendering…" : "Render now";
+    els.cancel.hidden = !s.inProgress;
+
+    if (s.phase === "complete" || s.phase === "failed" || s.phase === "cancelled") {
+        if (s.phase === "failed" && s.error)        showMsg("Failed: " + s.error);
+        else if (s.phase === "cancelled")           showMsg("Cancelled. Next render resumes from this point.");
+        else if (s.phase === "complete")            showMsg("Render complete.", true);
+    }
+}
+
+function phaseLabel(phase) {
+    switch (phase) {
+        case "downloading": return "Downloading CLI";
+        case "extracting":  return "Extracting CLI";
+        case "configuring": return "Configuring";
+        case "rendering":   return "Rendering";
+        case "complete":    return "Complete";
+        case "failed":      return "Failed";
+        case "cancelled":   return "Cancelled";
+        default:            return "Idle";
+    }
+}
+
+function showMsg(text, ok = false) {
+    els.msg.className = ok ? "acct-msg ok" : "acct-msg";
+    els.msg.textContent = text;
+}
+
+export function setupMap() {
+    els.phase   = document.getElementById("mapPhase");
+    els.lastLog = document.getElementById("mapLastLog");
+    els.render  = document.getElementById("mapRender");
+    els.cancel  = document.getElementById("mapCancel");
+    els.open    = document.getElementById("mapOpen");
+    els.msg     = document.getElementById("mapMsg");
+    if (!els.render) return;
+
+    els.cancel.addEventListener("click", async () => {
+        if (!confirm("Cancel the render? It's resumable -- next time you click Render, BlueMap continues from where it stopped.")) return;
+        try {
+            const res = await fetch("/api/map/cancel", { method: "POST" });
+            const body = await res.json().catch(() => ({}));
+            if (!res.ok || body.ok === false) showMsg(body.error || `Error ${res.status}`);
+            else { showMsg("Cancelling…"); tick(); }
+        } catch (e) { showMsg(e.message); }
+    });
+
+    // Track modal open/close so we can poll faster when the user is watching.
+    const modal = document.getElementById("modalMap");
+    new MutationObserver(() => {
+        modalOpen = !modal.hidden;
+        if (modalOpen) tick();
+    }).observe(modal, { attributes: true, attributeFilter: ["hidden"] });
+
+    els.render.addEventListener("click", async () => {
+        showMsg("Starting render…");
+        els.render.disabled = true;
+        try {
+            const res = await fetch("/api/map/render", { method: "POST" });
+            const body = await res.json().catch(() => ({}));
+            if (!res.ok || body.ok === false) {
+                showMsg(body.error || `Error ${res.status}`);
+                els.render.disabled = false;
+                return;
+            }
+            tick();
+        } catch (e) { showMsg(e.message); els.render.disabled = false; }
+    });
+
+    els.open.addEventListener("click", () => {
+        if (!lastHasOutput) {
+            showMsg("No map output yet -- click Render now first.");
+            return;
+        }
+        window.open("/map/", "_blank", "noopener");
+    });
+
+    tick();
+    setPolling(3000); // light poll keeps the badge fresh + catches background renders
+}

server/wwwroot/modules/modal.js

@@ -0,0 +1,57 @@
+// Tiny modal helper. Registers a single document-level Esc + backdrop-click
+// handler so individual modals don't have to. Public API: openModal(id) /
+// closeModal(id) / closeAllModals().
+"use strict";
+
+let bound = false;
+
+function bindGlobal() {
+    if (bound) return;
+    bound = true;
+    document.addEventListener("keydown", e => {
+        if (e.key === "Escape") closeAllModals();
+    });
+    document.addEventListener("click", e => {
+        // Backdrop click closes the topmost open modal.
+        const backdrop = e.target.closest(".modal-backdrop");
+        if (backdrop) closeModal(backdrop.parentElement.id);
+        const closeBtn = e.target.closest(".modal-close");
+        if (closeBtn) closeModal(closeBtn.closest(".modal").id);
+    });
+}
+
+export function openModal(id) {
+    bindGlobal();
+    const m = document.getElementById(id);
+    if (!m) return;
+    m.hidden = false;
+    document.body.classList.add("modal-open");
+    // Focus first input/button for keyboard users.
+    setTimeout(() => {
+        const focusable = m.querySelector("input, button:not(.modal-close), select, textarea");
+        focusable?.focus();
+    }, 50);
+}
+
+export function closeModal(id) {
+    const m = document.getElementById(id);
+    if (!m) return;
+    m.hidden = true;
+    if (!document.querySelector(".modal:not([hidden])")) {
+        document.body.classList.remove("modal-open");
+    }
+}
+
+export function closeAllModals() {
+    document.querySelectorAll(".modal:not([hidden])").forEach(m => m.hidden = true);
+    document.body.classList.remove("modal-open");
+}
+
+/// Wires `data-open-modal="someId"` on any element to opening the modal.
+export function setupModalTriggers() {
+    bindGlobal();
+    document.addEventListener("click", e => {
+        const trigger = e.target.closest("[data-open-modal]");
+        if (trigger) openModal(trigger.getAttribute("data-open-modal"));
+    });
+}

server/wwwroot/modules/panels.js

@@ -0,0 +1,117 @@
+// Status / players / whitelist sidebar panels. Polled (not streamed) because the
+// data they show changes infrequently. Logs use SSE -- see console.js.
+"use strict";
+
+import { api, escapeHtml } from "./api.js";
+import { state, rebuildKnownPlayers } from "./state.js";
+
+export async function tickStatus() {
+    const pill = document.getElementById("statusPill");
+    const text = document.getElementById("statusText");
+    const memEl = document.getElementById("memUsage");
+    const memBar = document.getElementById("memBar");
+    const cpuCur = document.getElementById("cpuCurrent");
+    const cpuBar = document.getElementById("cpuBar");
+    const cpuMax = document.getElementById("cpuMax");
+    const cpuAvg = document.getElementById("cpuAvg");
+
+    function renderResources(s) {
+        if (s.memoryBytes != null) {
+            const usedGB = s.memoryBytes / (1024 ** 3);
+            const maxGB = s.memoryMaxMB ? s.memoryMaxMB / 1024 : null;
+            memEl.textContent = maxGB
+                ? `${usedGB.toFixed(2)} / ${maxGB.toFixed(1)} GB`
+                : `${usedGB.toFixed(2)} GB`;
+            memBar.style.width = maxGB ? `${Math.min(100, (usedGB / maxGB) * 100)}%` : "0%";
+        } else {
+            memEl.textContent = "--";
+            memBar.style.width = "0%";
+        }
+        if (s.cpu) {
+            cpuCur.textContent = `${s.cpu.current.toFixed(1)} %`;
+            cpuBar.style.width = `${Math.min(100, s.cpu.current)}%`;
+            cpuMax.textContent = `${s.cpu.max.toFixed(1)}%`;
+            cpuAvg.textContent = `${s.cpu.avg.toFixed(1)}%`;
+        } else {
+            cpuCur.textContent = "--";
+            cpuBar.style.width = "0%";
+            cpuMax.textContent = "--";
+            cpuAvg.textContent = "--";
+        }
+    }
+
+    try {
+        const s = await api("/api/status");
+        if (s.running) {
+            pill.className = "status-pill online";
+            text.textContent = "Online";
+            document.getElementById("pid").textContent = s.pid ?? "--";
+            const secs = Math.floor(s.uptime ?? 0);
+            const h = Math.floor(secs / 3600), m = Math.floor((secs % 3600) / 60);
+            document.getElementById("uptime").textContent = `${h}h ${m}m`;
+            renderResources(s);
+        } else {
+            pill.className = "status-pill offline";
+            text.textContent = "Offline";
+            document.getElementById("pid").textContent = "--";
+            document.getElementById("uptime").textContent = "--";
+            renderResources({ memoryBytes: null, cpu: null, memoryMaxMB: null });
+        }
+        const pv = s.packVersion;
+        document.getElementById("packVersion").textContent = pv?.name ? `${pv.name} v${pv.version}` : "--";
+
+        // World size -- even when server is offline we can still report disk usage.
+        const worldEl = document.getElementById("worldSize");
+        if (worldEl) {
+            const b = s.worldSizeBytes;
+            if (b == null || b === 0) worldEl.textContent = "--";
+            else if (b < 1024 * 1024)              worldEl.textContent = `${(b / 1024).toFixed(0)} KB`;
+            else if (b < 1024 * 1024 * 1024)       worldEl.textContent = `${(b / (1024 * 1024)).toFixed(1)} MB`;
+            else                                    worldEl.textContent = `${(b / (1024 * 1024 * 1024)).toFixed(2)} GB`;
+        }
+    } catch {
+        pill.className = "status-pill offline";
+        text.textContent = "Disconnected";
+    }
+}
+
+export async function tickPlayers() {
+    try {
+        const p = await api("/api/players");
+        state.onlinePlayers = (p.players || []).slice();
+        document.getElementById("playerCount").textContent = p.online >= 0 ? p.online : "?";
+        const list = document.getElementById("players");
+        if (state.onlinePlayers.length === 0) {
+            list.innerHTML = '<li class="empty-state">No-one online</li>';
+        } else {
+            list.innerHTML = state.onlinePlayers.map(n => `<li>${escapeHtml(n)}<span></span></li>`).join("");
+        }
+    } catch {}
+    rebuildKnownPlayers();
+}
+
+export async function tickWhitelist() {
+    try {
+        const w = await api("/api/whitelist");
+        state.whitelistedPlayers = (w.players || []).slice();
+        const list = document.getElementById("whitelist");
+        if (state.whitelistedPlayers.length === 0) {
+            list.innerHTML = '<li class="empty-state">No players whitelisted yet</li>';
+        } else {
+            list.innerHTML = state.whitelistedPlayers.map(n =>
+                `<li>${escapeHtml(n)}<button data-name="${escapeHtml(n)}" class="wl-remove">Remove</button></li>`
+            ).join("");
+        }
+    } catch {}
+    rebuildKnownPlayers();
+}
+
+// MC takes ~1-2 s to look up a UUID via Mojang and write whitelist.json.
+// Refresh shortly after a user-triggered add/remove instead of waiting for the
+// 30-second polling tick.
+let pendingRefresh;
+export function refreshWhitelistSoon() {
+    clearTimeout(pendingRefresh);
+    pendingRefresh = setTimeout(tickWhitelist, 1500);
+    setTimeout(tickWhitelist, 4000); // belt-and-braces if Mojang is slow
+}

server/wwwroot/modules/pregen.js

@@ -0,0 +1,222 @@
+// World pre-generation controls + live status display.
+//
+// We use the canonical config-then-start sequence rather than the all-in-one
+// `chunky start <world> <shape> <cx> <cz> <r>` form because the all-in-one
+// form's argument order varies between Chunky versions, and Brigadier silently
+// prints the usage hint instead of erroring when it doesn't match.
+//
+// Status is parsed from Chunky's own log lines (re-broadcast by console.js as
+// the `serverlog` custom event) -- no separate polling endpoint is needed.
+//
+// Chunky is intentionally only invoked from this panel -- it can punch holes
+// in chunks if it crashes mid-run, so we don't want it ticking on its own.
+"use strict";
+
+import { apiJson } from "./api.js";
+
+async function send(cmd) {
+    await apiJson("/api/command", { command: cmd });
+}
+
+async function startPregen(radius) {
+    await send("chunky world minecraft:overworld");
+    await send("chunky shape square");
+    await send("chunky center 0 0");
+    await send(`chunky radius ${radius}`);
+    await send("chunky start");
+}
+
+// ─────────── status display ───────────
+
+const els = {};
+
+function setState(label, cssClass) {
+    if (!els.state) return;
+    els.state.textContent = label;
+    els.state.className = "val " + cssClass;
+    applyButtonStates(cssClass);
+}
+
+/// Enable/disable the Start/Pause/Resume/Cancel buttons based on the current
+/// pregen state. Called whenever setState changes the displayed status.
+function applyButtonStates(cssClass) {
+    if (!els.btnStart) return;
+    // Map the state CSS class to a logical state name. Default = idle.
+    let s = "idle";
+    if (cssClass === "pg-state-running")    s = "running";
+    else if (cssClass === "pg-state-paused") s = "paused";
+    else if (cssClass === "pg-state-cancelling") s = "cancelling";
+
+    els.btnStart.disabled    = s !== "idle";
+    els.btnPause.disabled    = s !== "running";
+    els.btnContinue.disabled = s !== "paused";
+    els.btnCancel.disabled   = !(s === "running" || s === "paused");
+}
+
+function resetMetrics() {
+    if (!els.progressFill) return;
+    els.progressFill.style.width = "0%";
+    els.progressText.textContent = "--";
+    els.chunks.textContent = "--";
+    els.rate.textContent = "--";
+    els.eta.textContent = "--";
+}
+
+// Parse a Chunky log line. Returns an object describing what changed, or null
+// if this line isn't a Chunky message we recognise (or is for a different world).
+//
+// Chunky supports one task per world running concurrently, so we narrow our
+// display to the overworld -- that's the only world the Start button targets,
+// and it keeps the UI sane if someone kicks off other worlds via raw command.
+//
+// Real Chunky lines look roughly like:
+//   "[Chunky] Task running for minecraft:overworld at 0,0. Progress: 12.50% (1234/9876 chunks), 45.20 cps, ETA: 0h 1m 30s"
+//   "[Chunky] Task started for minecraft:overworld."
+//   "[Chunky] Task stopped for minecraft:overworld."
+//   "[Chunky] Task paused for minecraft:overworld."
+//   "[Chunky] No task running."
+const TARGET_WORLD = "minecraft:overworld";
+
+function parseChunky(text) {
+    if (!/Chunky|chunky/.test(text)) return null;
+
+    // If a world is named, only react when it's the one we're tracking.
+    // Lines without a world (e.g. "No task running.") fall through.
+    const worldMatch = text.match(/(minecraft:[a-z_]+|the_nether|the_end|overworld)/i);
+    if (worldMatch) {
+        const w = worldMatch[1].toLowerCase();
+        const normalised = w.startsWith("minecraft:") ? w : `minecraft:${w}`;
+        if (normalised !== TARGET_WORLD) return null;
+    }
+
+    // State transitions
+    if (/Task started/i.test(text))   return { state: "running" };
+    if (/Task paused/i.test(text))    return { state: "paused" };
+    if (/Task (stopped|cancelled|canceled|completed|finished)/i.test(text))
+                                       return { state: "idle", clear: true };
+    if (/No task running/i.test(text)) return { state: "idle", clear: true };
+
+    // Progress line: try to extract whatever pieces are present
+    const out = {};
+    let matched = false;
+
+    const pct = text.match(/(\d+(?:\.\d+)?)\s*%/);
+    if (pct) { out.percent = parseFloat(pct[1]); matched = true; }
+
+    const chunks = text.match(/(\d[\d,]*)\s*\/\s*(\d[\d,]*)\s*chunks?/i);
+    if (chunks) {
+        out.done  = chunks[1].replace(/,/g, "");
+        out.total = chunks[2].replace(/,/g, "");
+        matched = true;
+    }
+
+    const cps = text.match(/(\d+(?:\.\d+)?)\s*cps/i);
+    if (cps) { out.cps = parseFloat(cps[1]); matched = true; }
+
+    const eta = text.match(/ETA[:\s]+([^,)\n]+?)(?=[,)\n]|$)/i);
+    if (eta) { out.eta = eta[1].trim(); matched = true; }
+
+    if (matched) { out.state = "running"; return out; }
+    return null;
+}
+
+function applyParsed(p) {
+    if (!els.state) return;
+    if (p.state === "running")  setState("Running",  "pg-state-running");
+    if (p.state === "paused")   setState("Paused",   "pg-state-paused");
+    if (p.state === "idle")     setState("Idle",     "pg-state-idle");
+    if (p.clear) resetMetrics();
+
+    if (p.percent != null) {
+        els.progressFill.style.width  = `${Math.min(100, p.percent)}%`;
+        els.progressText.textContent  = `${p.percent.toFixed(2)}%`;
+    }
+    if (p.done && p.total) {
+        const fmt = n => Number(n).toLocaleString();
+        els.chunks.textContent = `${fmt(p.done)} / ${fmt(p.total)}`;
+    }
+    if (p.cps  != null) els.rate.textContent = `${p.cps.toFixed(1)} chunks/s`;
+    if (p.eta)          els.eta.textContent  = p.eta;
+}
+
+function setupCollapsible() {
+    // Persist collapsed state per card across reloads via localStorage.
+    document.querySelectorAll(".card.collapsible").forEach(card => {
+        const id = card.id || "";
+        const storageKey = id ? `bs-collapsed:${id}` : null;
+        const startCollapsed = storageKey && localStorage.getItem(storageKey) === "1";
+        if (!startCollapsed) card.classList.add("expanded");
+        const toggle = card.querySelector(".collapsible-toggle");
+        if (!toggle) return;
+        toggle.addEventListener("click", () => {
+            card.classList.toggle("expanded");
+            if (storageKey) {
+                localStorage.setItem(storageKey,
+                    card.classList.contains("expanded") ? "0" : "1");
+            }
+        });
+    });
+}
+
+export function setupPregen() {
+    setupCollapsible();
+    els.state        = document.getElementById("pgState");
+    els.progressFill = document.getElementById("pgProgressFill");
+    els.progressText = document.getElementById("pgProgressText");
+    els.chunks       = document.getElementById("pgChunks");
+    els.rate         = document.getElementById("pgRate");
+    els.eta          = document.getElementById("pgEta");
+    els.btnStart     = document.getElementById("pgStart");
+    els.btnPause     = document.getElementById("pgPause");
+    els.btnContinue  = document.getElementById("pgContinue");
+    els.btnCancel    = document.getElementById("pgCancel");
+
+    // Idle by default -- disable everything except Start.
+    applyButtonStates("pg-state-idle");
+
+    const radiusInput = document.getElementById("pgRadius");
+
+    document.getElementById("pgStart").addEventListener("click", async () => {
+        const r = parseInt(radiusInput.value, 10);
+        if (!Number.isFinite(r) || r < 100) {
+            alert("Enter a radius of at least 100 blocks.");
+            return;
+        }
+        if (r > 20000 && !confirm(`Radius ${r} is large and may take hours. Continue?`)) {
+            return;
+        }
+        try {
+            setState("Starting…", "pg-state-running");
+            resetMetrics();
+            await startPregen(r);
+        } catch (e) {
+            setState("Idle", "pg-state-idle");
+            alert(e.message);
+        }
+    });
+
+    document.getElementById("pgPause").addEventListener("click", async () => {
+        try { await send("chunky pause"); } catch (e) { alert(e.message); }
+    });
+    document.getElementById("pgContinue").addEventListener("click", async () => {
+        try {
+            await send("chunky continue");
+            setState("Running", "pg-state-running");
+        } catch (e) { alert(e.message); }
+    });
+    document.getElementById("pgCancel").addEventListener("click", async () => {
+        if (!confirm("Cancel the current pre-generation run?")) return;
+        try {
+            setState("Cancelling…", "pg-state-cancelling");
+            await send("chunky cancel");
+        } catch (e) { alert(e.message); }
+    });
+
+    // Subscribe to the shared SSE re-broadcast from console.js
+    document.addEventListener("serverlog", e => {
+        const msg = e.detail?.m;
+        if (typeof msg !== "string") return;
+        const parsed = parseChunky(msg);
+        if (parsed) applyParsed(parsed);
+    });
+}

server/wwwroot/modules/serverControls.js

@@ -0,0 +1,16 @@
+// Start / stop buttons.
+"use strict";
+
+import { api } from "./api.js";
+
+export function setupServerControls() {
+    document.getElementById("btnStart").addEventListener("click", async () => {
+        try { await api("/api/server/start", { method: "POST" }); }
+        catch (e) { alert(e.message); }
+    });
+    document.getElementById("btnStop").addEventListener("click", async () => {
+        if (!confirm("Stop the server?")) return;
+        try { await api("/api/server/stop", { method: "POST" }); }
+        catch (e) { alert(e.message); }
+    });
+}

server/wwwroot/modules/settings.js

@@ -0,0 +1,135 @@
+// Server settings: read/write a curated subset of server.properties.
+// Changes require an MC restart -- Save writes only, Save & restart bounces MC.
+"use strict";
+
+import { api } from "./api.js";
+
+const els = {};
+
+// Map of input element ID -> server.properties key. Keeps the form ↔ file
+// translation in one place; new fields can be added by adding a row here +
+// matching elements in index.html.
+const FIELDS = [
+    { id: "ssfMotd",                 key: "motd",                  type: "string"  },
+    { id: "ssfGamemode",             key: "gamemode",              type: "string"  },
+    { id: "ssfDifficulty",           key: "difficulty",            type: "string"  },
+    { id: "ssfViewDistance",         key: "view-distance",         type: "int"     },
+    { id: "ssfSimulationDistance",   key: "simulation-distance",   type: "int"     },
+    { id: "ssfMaxPlayers",           key: "max-players",           type: "int"     },
+    { id: "ssfSpawnProtection",      key: "spawn-protection",      type: "int"     },
+    { id: "ssfPvp",                  key: "pvp",                   type: "bool"    },
+    { id: "ssfHardcore",             key: "hardcore",              type: "bool"    },
+    { id: "ssfAllowFlight",          key: "allow-flight",          type: "bool"    },
+    { id: "ssfWhiteList",            key: "white-list",            type: "bool"    },
+    { id: "ssfEnforceWhitelist",     key: "enforce-whitelist",     type: "bool"    },
+    { id: "ssfEnableCommandBlock",   key: "enable-command-block",  type: "bool"    },
+];
+
+function readForm() {
+    const out = {};
+    for (const f of FIELDS) {
+        const el = document.getElementById(f.id);
+        if (!el) continue;
+        if (f.type === "bool") out[f.key] = el.checked ? "true" : "false";
+        else if (f.type === "int") {
+            const v = parseInt(el.value, 10);
+            if (Number.isFinite(v)) out[f.key] = String(v);
+        } else {
+            out[f.key] = el.value;
+        }
+    }
+    return out;
+}
+
+function writeForm(values) {
+    for (const f of FIELDS) {
+        const el = document.getElementById(f.id);
+        if (!el) continue;
+        const v = values[f.key];
+        if (v === undefined) continue;
+        if (f.type === "bool") el.checked = (v === "true");
+        else el.value = v;
+    }
+}
+
+function renderSummary(values) {
+    document.getElementById("ssMotd").textContent       = values["motd"]       ?? "--";
+    document.getElementById("ssDifficulty").textContent = values["difficulty"] ?? "--";
+    document.getElementById("ssDistances").textContent  =
+        `${values["view-distance"] ?? "--"} / ${values["simulation-distance"] ?? "--"}`;
+    document.getElementById("ssMaxPlayers").textContent = values["max-players"] ?? "--";
+    const wl = values["white-list"] === "true";
+    const enf = values["enforce-whitelist"] === "true";
+    document.getElementById("ssWhitelist").textContent =
+        wl ? (enf ? "enforced" : "enabled") : "off";
+}
+
+async function refresh() {
+    try {
+        const data = await api("/api/server/settings");
+        renderSummary(data.values || {});
+        writeForm(data.values || {});
+    } catch { /* ignore -- panel just shows last-known */ }
+}
+
+async function postSettings() {
+    const payload = readForm();
+    const res = await fetch("/api/server/settings", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(payload),
+    });
+    return { ok: res.ok, body: await res.json().catch(() => ({})) };
+}
+
+function showMsg(text, ok = false) {
+    els.msg.className = ok ? "acct-msg ok" : "acct-msg";
+    els.msg.textContent = text;
+}
+
+export function setupSettings() {
+    els.msg     = document.getElementById("ssMsg");
+    els.save    = document.getElementById("ssSave");
+    els.restart = document.getElementById("ssRestart");
+    if (!els.save) return;
+
+    els.save.addEventListener("click", async () => {
+        showMsg("Saving...");
+        els.save.disabled = true;
+        try {
+            const r = await postSettings();
+            if (!r.ok || r.body.ok === false) {
+                showMsg(r.body.error || `Error ${r.body.status ?? ""}`);
+                return;
+            }
+            showMsg(r.body.restartRequired
+                ? "Saved. Restart for changes to take effect."
+                : "Saved.", true);
+            refresh();
+        } catch (e) { showMsg(e.message); }
+        finally { els.save.disabled = false; }
+    });
+
+    els.restart.addEventListener("click", async () => {
+        if (!confirm("Save changes and restart the server now? Players will be disconnected briefly.")) return;
+        showMsg("Saving + restarting...");
+        els.save.disabled = true; els.restart.disabled = true;
+        try {
+            const r = await postSettings();
+            if (!r.ok || r.body.ok === false) {
+                showMsg(r.body.error || `Save failed: ${r.body.status ?? ""}`);
+                return;
+            }
+            const rr = await fetch("/api/server/restart", { method: "POST" });
+            const rb = await rr.json().catch(() => ({}));
+            if (!rr.ok || rb.ok === false) showMsg("Saved, but restart failed: " + (rb.error || rr.status));
+            else showMsg("Saved + restarting. New settings live in ~30s.", true);
+            refresh();
+        } catch (e) { showMsg(e.message); }
+        finally { els.save.disabled = false; els.restart.disabled = false; }
+    });
+
+    refresh();
+    // Light poll: pick up out-of-band edits to server.properties.
+    setInterval(refresh, 30000);
+}

server/wwwroot/modules/state.js

@@ -0,0 +1,18 @@
+// Shared in-memory state -- the union of online + whitelisted players is what
+// tab-completion matches against, so we keep it centralised here.
+"use strict";
+
+export const state = {
+    onlinePlayers: [],
+    whitelistedPlayers: [],
+    knownPlayers: [], // sorted union, for autocomplete
+    cmdHistory: [],
+    cmdHistoryIdx: -1,
+};
+
+export function rebuildKnownPlayers() {
+    const set = new Set();
+    state.onlinePlayers.forEach(n => set.add(n));
+    state.whitelistedPlayers.forEach(n => set.add(n));
+    state.knownPlayers = [...set].sort((a, b) => a.toLowerCase().localeCompare(b.toLowerCase()));
+}

server/wwwroot/modules/update.js

@@ -0,0 +1,138 @@
+// Modpack update controls.
+//
+// The card hides itself when there's no update available and reveals when the
+// manifest reports a newer pack version. Polls /api/update/status (every 5 s
+// when idle, every 1 s when an update is in-flight) to keep state fresh.
+"use strict";
+
+import { api, apiJson } from "./api.js";
+
+const els = {};
+let pollTimer = null;
+let pollInterval = 5000;
+
+function setPolling(intervalMs) {
+    if (intervalMs === pollInterval && pollTimer) return;
+    if (pollTimer) clearInterval(pollTimer);
+    pollInterval = intervalMs;
+    pollTimer = setInterval(tick, intervalMs);
+}
+
+async function tick() {
+    let s;
+    try { s = await api("/api/update/status"); }
+    catch { return; }
+
+    els.current.textContent   = s.current ?? "--";
+    els.available.textContent = s.available ?? "--";
+
+    const card = els.card;
+    if (s.needsUpdate || s.inProgress) {
+        card.hidden = false;
+        card.classList.toggle("has-update", s.needsUpdate && !s.inProgress);
+    } else {
+        card.hidden = true;
+    }
+
+    if (s.inProgress) {
+        els.progress.hidden = false;
+        els.start.disabled = true;
+        els.delay.disabled = true;
+        els.phase.textContent = phaseLabel(s.phase);
+
+        const showCancel = s.phase === "countdown";
+        els.cancel.hidden = !showCancel;
+
+        if (s.phase === "countdown" && s.countdownTotal > 0) {
+            const elapsed = s.countdownTotal - s.countdownRemaining;
+            const pct = (elapsed / s.countdownTotal) * 100;
+            els.fill.style.width = `${pct}%`;
+            els.status.textContent = `Restarting in ${formatSeconds(s.countdownRemaining)}`;
+        } else {
+            // Indeterminate during sync / loader install / start phases --
+            // just show 100% and a phase-specific status string.
+            els.fill.style.width = "100%";
+            els.status.textContent = phaseStatus(s.phase);
+        }
+        setPolling(1000);
+    } else {
+        els.progress.hidden = true;
+        els.start.disabled = !s.needsUpdate;
+        els.delay.disabled = false;
+        if (s.phase === "failed" && s.error) {
+            els.progress.hidden = false;
+            els.phase.textContent = "FAILED";
+            els.status.textContent = s.error;
+            els.fill.style.width = "0%";
+        }
+        setPolling(5000);
+    }
+}
+
+function phaseLabel(phase) {
+    switch (phase) {
+        case "countdown":          return "COUNTDOWN";
+        case "stopping":           return "STOPPING";
+        case "syncing":            return "SYNCING MODS";
+        case "installing_loader":  return "INSTALLING LOADER";
+        case "starting":           return "STARTING";
+        case "complete":           return "COMPLETE";
+        case "failed":             return "FAILED";
+        case "cancelled":          return "CANCELLED";
+        default:                   return "WORKING";
+    }
+}
+
+function phaseStatus(phase) {
+    switch (phase) {
+        case "stopping":           return "Stopping Minecraft cleanly...";
+        case "syncing":            return "Syncing mods from manifest...";
+        case "installing_loader":  return "Re-running NeoForge installer...";
+        case "starting":           return "Starting Minecraft...";
+        case "complete":           return "Update complete.";
+        default:                   return "";
+    }
+}
+
+function formatSeconds(s) {
+    if (s < 60) return `${s}s`;
+    const m = Math.floor(s / 60), r = s % 60;
+    return `${m}m ${String(r).padStart(2, "0")}s`;
+}
+
+export function setupUpdate() {
+    els.card      = document.getElementById("updateCard");
+    els.current   = document.getElementById("updCurrent");
+    els.available = document.getElementById("updAvailable");
+    els.delay     = document.getElementById("updDelay");
+    els.start     = document.getElementById("updStart");
+    els.progress  = document.getElementById("updProgress");
+    els.phase     = document.getElementById("updPhaseLabel");
+    els.fill      = document.getElementById("updProgressFill");
+    els.status    = document.getElementById("updStatusText");
+    els.cancel    = document.getElementById("updCancel");
+
+    els.start.addEventListener("click", async () => {
+        const delay = parseInt(els.delay.value, 10);
+        if (!Number.isFinite(delay) || delay < 0) {
+            alert("Enter a non-negative warning duration.");
+            return;
+        }
+        if (!confirm(`Update modpack? Players get a ${delay}s warning, then the server restarts.`)) return;
+        try {
+            await apiJson("/api/update/start", { delaySeconds: delay });
+            await tick();
+        } catch (e) { alert(e.message); }
+    });
+
+    els.cancel.addEventListener("click", async () => {
+        if (!confirm("Cancel the countdown? Update will be aborted; server stays running.")) return;
+        try {
+            await apiJson("/api/update/cancel", {});
+            await tick();
+        } catch (e) { alert(e.message); }
+    });
+
+    tick();
+    setPolling(5000);
+}

server/wwwroot/modules/whitelist.js

@@ -0,0 +1,86 @@
+// Whitelist add / remove via the API; refreshes the panel display shortly after
+// each action (server takes ~1-2 s to look up UUID via Mojang and write whitelist.json).
+"use strict";
+
+import { api, apiJson, escapeHtml } from "./api.js";
+
+export function setupWhitelistActions(refreshSoon) {
+    const wlInput = document.getElementById("wlInput");
+    document.getElementById("wlAdd").addEventListener("click", () => addWhitelisted(refreshSoon));
+    wlInput.addEventListener("keydown", e => { if (e.key === "Enter") addWhitelisted(refreshSoon); });
+
+    // Delegated removal -- list items are re-rendered each tick, no static binding.
+    document.getElementById("whitelist").addEventListener("click", async e => {
+        const btn = e.target.closest(".wl-remove");
+        if (!btn) return;
+        const name = btn.dataset.name;
+        if (!name) return;
+        if (!confirm(`Remove ${name} from whitelist?`)) return;
+        try {
+            await apiJson("/api/whitelist/remove", { name });
+            refreshSoon();
+        } catch (err) { alert(err.message); }
+    });
+
+    // Pending whitelist requests from friends. Approve adds to whitelist + clears
+    // the request; Deny just marks denied so the friend's launcher knows.
+    const reqsList  = document.getElementById("wlRequests");
+    const reqsBlock = document.getElementById("wlRequestsBlock");
+    const reqsBadge = document.getElementById("wlReqBadge");
+
+    reqsList?.addEventListener("click", async e => {
+        const btn = e.target.closest("button[data-req-action]");
+        if (!btn) return;
+        const name   = btn.dataset.name;
+        const action = btn.dataset.reqAction; // "approve" | "deny"
+        if (!name || !action) return;
+        if (action === "deny" && !confirm(`Deny ${name}'s request?`)) return;
+        try {
+            await apiJson(`/api/whitelist/requests/${action}`, { name });
+            await refreshRequests();
+            // Approving fires /whitelist add via stdin -- let the server-side write
+            // ~1-2 s of grace before re-reading whitelist.json.
+            if (action === "approve") refreshSoon();
+        } catch (err) { alert(err.message); }
+    });
+
+    async function refreshRequests() {
+        if (!reqsList || !reqsBlock || !reqsBadge) return;
+        let data;
+        try { data = await api("/api/whitelist/requests"); }
+        catch { return; }
+        const reqs = data.requests || [];
+        if (reqs.length === 0) {
+            reqsBlock.hidden = true;
+            reqsBadge.hidden = true;
+            return;
+        }
+        reqsBlock.hidden = false;
+        reqsBadge.hidden = false;
+        reqsBadge.textContent = String(reqs.length);
+        reqsList.innerHTML = reqs.map(r => `
+            <li>
+                <div class="wl-req-meta">${escapeHtml(r.username)}</div>
+                ${r.message ? `<div class="wl-req-msg">"${escapeHtml(r.message)}"</div>` : ""}
+                <div class="wl-req-actions">
+                    <button data-req-action="approve" data-name="${escapeHtml(r.username)}">Approve</button>
+                    <button class="ghost-btn" data-req-action="deny" data-name="${escapeHtml(r.username)}">Deny</button>
+                </div>
+            </li>
+        `).join("");
+    }
+
+    refreshRequests();
+    setInterval(refreshRequests, 15000);
+}
+
+async function addWhitelisted(refreshSoon) {
+    const inp = document.getElementById("wlInput");
+    const name = inp.value.trim();
+    if (!name) return;
+    try {
+        await apiJson("/api/whitelist/add", { name });
+        inp.value = "";
+        refreshSoon();
+    } catch (e) { alert(e.message); }
+}

server/wwwroot/styles.css

@@ -0,0 +1,521 @@
+:root {
+    --bg-deep: #070b16;
+    --bg: #0b1220;
+    --card: #13192a;
+    --card-edge: #2a3552;
+    --text: #e8dfc8;
+    --text-muted: #7a8497;
+    --brass: #d4a24c;
+    --brass-hi: #e8b95c;
+    --brass-lo: #5c4519;
+    --magic: #5dd4e8;
+    --danger: #b94228;
+    --ok: #4ade80;
+}
+
+html, body {
+    margin: 0; padding: 0;
+    background: var(--bg);
+    color: var(--text);
+    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
+    min-height: 100vh;
+}
+
+.topbar {
+    display: flex; align-items: center; justify-content: space-between;
+    padding: 14px 22px;
+    border-bottom: 1px solid var(--brass-lo);
+    background: linear-gradient(180deg, #0f1626 0%, var(--bg-deep) 100%);
+}
+.topbar h1 {
+    font-size: 16px; margin: 0;
+    color: var(--brass-hi);
+    font-weight: 600; letter-spacing: 0.04em;
+}
+
+.status-pill {
+    display: inline-flex; align-items: center; gap: 8px;
+    padding: 6px 12px; border-radius: 99px;
+    background: var(--bg-deep); border: 1px solid var(--card-edge);
+    font-size: 13px;
+}
+.status-pill .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--text-muted); }
+.status-pill.online .dot { background: var(--ok); box-shadow: 0 0 8px var(--ok); }
+.status-pill.offline .dot { background: var(--danger); }
+
+.layout {
+    max-width: 1400px; margin: 22px auto; padding: 0 22px;
+    display: grid; grid-template-columns: 280px 1fr 280px; gap: 18px;
+}
+/* Below the 3-column breakpoint: drop the right sidebar to a new full-width row
+   under the main + left sidebar so cards still get reasonable horizontal space. */
+@media (max-width: 1100px) {
+    .layout { grid-template-columns: 280px 1fr; }
+    .aside-right { grid-column: 1 / -1; }
+}
+@media (max-width: 800px) {
+    .layout { grid-template-columns: 1fr; }
+    .aside-right { grid-column: 1 / -1; }
+}
+
+.card {
+    background: linear-gradient(180deg, #13192a 0%, #0a0f1a 100%);
+    border: 1px solid var(--brass-lo);
+    border-radius: 8px;
+    padding: 18px;
+}
+.card + .card { margin-top: 14px; }
+.card h2 {
+    margin: 0 0 14px;
+    font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase;
+    color: var(--brass-hi); font-weight: 600;
+}
+
+.stat-row { display: flex; justify-content: space-between; margin: 6px 0; font-size: 13px; }
+.stat-row .key { color: var(--text-muted); }
+.stat-row .val { color: var(--text); font-family: "SF Mono", Consolas, monospace; }
+
+.name-list { list-style: none; padding: 0; margin: 0; }
+.name-list li {
+    padding: 6px 8px; background: var(--bg-deep); border-radius: 4px;
+    margin-bottom: 4px; font-size: 13px;
+    display: flex; align-items: center; justify-content: space-between;
+}
+.name-list li button {
+    background: transparent; border: 1px solid var(--card-edge);
+    color: var(--text-muted); padding: 2px 8px; font-size: 11px;
+    border-radius: 3px; cursor: pointer;
+}
+.name-list li button:hover { color: var(--danger); border-color: var(--danger); }
+.empty-state { color: var(--text-muted); font-size: 13px; padding: 8px 0; font-style: italic; }
+
+.console-pane {
+    background: #050810;
+    border: 1px solid var(--card-edge);
+    border-radius: 4px;
+    padding: 12px;
+    font-family: "SF Mono", Consolas, "Cascadia Mono", monospace;
+    font-size: 12px; line-height: 1.4;
+    color: #b7c0d6;
+    height: 480px; overflow-y: auto;
+    white-space: pre-wrap; word-break: break-word;
+}
+.console-pane .err { color: #ff8a72; }
+
+.input-row { display: flex; gap: 8px; margin-top: 10px; }
+.input-wrap {
+    flex: 1; position: relative;
+    background: var(--bg-deep);
+    border: 1px solid var(--card-edge);
+    border-radius: 4px;
+}
+.input-wrap:focus-within { border-color: var(--brass); }
+
+.ghost {
+    position: absolute; inset: 0;
+    padding: 8px 12px;
+    font-family: "SF Mono", Consolas, monospace; font-size: 13px;
+    line-height: normal;
+    color: var(--text-muted);
+    pointer-events: none;
+    white-space: pre;
+    overflow: hidden;
+    opacity: 0.55;
+}
+.ghost .typed { color: transparent; }
+
+.input-wrap input {
+    width: 100%; box-sizing: border-box;
+    background: transparent;
+    border: none;
+    color: var(--text);
+    padding: 8px 12px;
+    font-family: "SF Mono", Consolas, monospace; font-size: 13px;
+    position: relative;
+}
+.input-wrap input:focus { outline: none; }
+/* Hide the browser's built-in number-input spinner -- looks out of place against the dark theme */
+.input-wrap input[type="number"]::-webkit-inner-spin-button,
+.input-wrap input[type="number"]::-webkit-outer-spin-button {
+    -webkit-appearance: none; margin: 0;
+}
+.input-wrap input[type="number"] { -moz-appearance: textfield; }
+
+/* Suggestion dropdown -- shown below the command input with multiple matches */
+.suggest-list {
+    position: absolute;
+    top: calc(100% + 4px);
+    left: 0; right: 0;
+    background: var(--bg-deep);
+    border: 1px solid var(--brass-lo);
+    border-radius: 4px;
+    max-height: 220px;
+    overflow-y: auto;
+    z-index: 10;
+    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.4);
+    display: none;
+}
+.suggest-list.show { display: block; }
+.suggest-item {
+    padding: 7px 12px;
+    cursor: pointer;
+    font-family: "SF Mono", Consolas, monospace;
+    font-size: 13px;
+    color: var(--text);
+    display: flex;
+    align-items: baseline;
+    justify-content: space-between;
+    gap: 12px;
+}
+.suggest-item + .suggest-item {
+    border-top: 1px solid #1a2436;
+}
+.suggest-item:hover, .suggest-item.active {
+    background: var(--card);
+    color: var(--brass-hi);
+}
+.suggest-item .args {
+    color: var(--text-muted);
+    font-size: 11px;
+    font-style: italic;
+}
+.suggest-item .args em { font-style: normal; color: var(--brass); }
+.suggest-empty { padding: 8px 12px; color: var(--text-muted); font-size: 12px; font-style: italic; }
+
+.hint {
+    font-size: 11px; color: var(--text-muted);
+    padding: 6px 0 0 4px; min-height: 16px;
+}
+.hint kbd {
+    background: var(--bg-deep); border: 1px solid var(--card-edge);
+    padding: 1px 4px; border-radius: 2px; font-size: 10px;
+}
+
+button {
+    background: linear-gradient(180deg, var(--brass-hi) 0%, var(--brass) 50%, var(--brass-lo) 100%);
+    color: #1a140f;
+    border: 1px solid var(--brass-lo);
+    padding: 8px 16px; border-radius: 4px;
+    font-weight: 600; cursor: pointer; font-size: 13px;
+}
+button:hover { filter: brightness(1.1); }
+button.danger {
+    background: linear-gradient(180deg, #d65a3e 0%, var(--danger) 50%, #6a2814 100%);
+    color: #fff;
+    border-color: #6a2814;
+}
+button.ghost-btn {
+    background: var(--bg-deep);
+    color: var(--text);
+    border-color: var(--card-edge);
+}
+
+.actions { display: flex; gap: 8px; flex-wrap: wrap; }
+.footer { color: var(--text-muted); font-size: 11px; text-align: center; padding: 22px; }
+
+/* Modal dialogs (Pregen / Backups / Wipe / etc.) */
+.modal {
+    position: fixed; inset: 0; z-index: 50;
+    display: flex; align-items: center; justify-content: center;
+    padding: 20px;
+}
+.modal[hidden] { display: none; }
+.modal-backdrop {
+    position: absolute; inset: 0;
+    background: rgba(7, 11, 22, 0.85);
+    backdrop-filter: blur(2px);
+}
+.modal-dialog {
+    position: relative;
+    background: linear-gradient(180deg, #13192a 0%, #0a0f1a 100%);
+    border: 1px solid var(--brass-lo);
+    border-radius: 8px;
+    padding: 24px;
+    width: 100%; max-width: 520px;
+    max-height: 85vh; overflow-y: auto;
+    box-shadow: 0 14px 40px rgba(0, 0, 0, 0.6);
+}
+.modal-dialog.danger { border-color: #6a2814; }
+.modal-header {
+    display: flex; justify-content: space-between; align-items: center;
+    margin-bottom: 14px;
+    padding-bottom: 10px;
+    border-bottom: 1px solid var(--card-edge);
+}
+.modal-header h2 {
+    margin: 0;
+    font-size: 13px; letter-spacing: 0.08em; text-transform: uppercase;
+    color: var(--brass-hi); font-weight: 600;
+}
+.modal-dialog.danger .modal-header h2 { color: #d65a3e; }
+.modal-close {
+    background: transparent; border: none;
+    color: var(--text-muted); font-size: 22px; line-height: 1;
+    cursor: pointer; padding: 0 4px;
+}
+.modal-close:hover { color: var(--text); }
+
+/* Trigger button list (the "World" card, etc.) */
+.trigger-list {
+    display: flex; flex-direction: column; gap: 6px;
+}
+.trigger-list button {
+    width: 100%; text-align: left;
+    display: flex; align-items: center; justify-content: space-between;
+    gap: 8px;
+}
+.trigger-list .badge {
+    background: var(--bg-deep); border: 1px solid var(--card-edge);
+    color: var(--text-muted);
+    padding: 1px 6px; border-radius: 99px;
+    font-size: 10px; font-weight: 500;
+}
+.trigger-list .badge.ok    { color: var(--ok);    border-color: var(--ok); }
+.trigger-list .badge.warn  { color: var(--brass-hi); border-color: var(--brass-lo); }
+
+/* Topbar server icon */
+.topbar-icon {
+    height: 28px; width: 28px;
+    margin-right: 10px;
+    image-rendering: -webkit-optimize-contrast;
+}
+.topbar-left {
+    display: flex; align-items: center;
+}
+
+/* Login overlay */
+.login-overlay {
+    position: fixed; inset: 0; z-index: 100;
+    background: rgba(7, 11, 22, 0.92);
+    display: flex; align-items: center; justify-content: center;
+    backdrop-filter: blur(2px);
+}
+.login-overlay[hidden] { display: none; }
+.login-box {
+    background: linear-gradient(180deg, #13192a 0%, #0a0f1a 100%);
+    border: 1px solid var(--brass-lo);
+    border-radius: 8px;
+    padding: 28px 32px;
+    width: 320px;
+    box-shadow: 0 14px 40px rgba(0, 0, 0, 0.6);
+}
+.login-box h2 {
+    margin: 0 0 4px;
+    font-size: 16px; letter-spacing: 0.04em;
+    color: var(--brass-hi); font-weight: 600;
+}
+.login-box p {
+    margin: 0 0 16px; color: var(--text-muted); font-size: 13px;
+}
+.login-box .input-wrap { margin-bottom: 12px; }
+.login-box button { width: 100%; }
+.login-error { color: var(--danger); font-size: 12px; min-height: 14px; padding-top: 8px; }
+
+/* Account card */
+.acct-form { font-size: 12px; }
+.acct-msg { font-size: 12px; min-height: 14px; margin-top: 8px; color: var(--danger); }
+.acct-msg.ok { color: var(--ok); }
+
+/* Modpack update card */
+#updateCard .update-note {
+    font-size: 12px; color: var(--text-muted);
+    margin: 10px 0 0; line-height: 1.4;
+}
+#updateCard .update-progress { margin-top: 14px; padding-top: 12px; border-top: 1px solid var(--card-edge); }
+#updateCard .update-phase {
+    font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase;
+    color: var(--brass-hi); font-weight: 600; margin-bottom: 6px;
+}
+#updateCard .update-status { font-size: 12px; color: var(--text); margin-top: 6px; }
+#updateCard .update-progress button { margin-top: 10px; }
+/* Pulsing border highlight when an update is available */
+#updateCard.has-update {
+    border-color: var(--brass);
+    box-shadow: 0 0 0 1px var(--brass-lo), 0 0 18px rgba(212, 162, 76, 0.18);
+}
+
+/* Resources card -- Memory + CPU with progress bars */
+.res-block { margin-bottom: 14px; }
+.res-block:last-child { margin-bottom: 0; }
+.res-label {
+    display: flex; justify-content: space-between; align-items: baseline;
+    font-size: 12px; color: var(--text-muted);
+    margin-bottom: 6px;
+}
+.res-label .res-val { color: var(--text); font-family: "SF Mono", Consolas, monospace; }
+.res-bar {
+    height: 6px;
+    background: var(--bg-deep);
+    border: 1px solid var(--card-edge);
+    border-radius: 3px;
+    overflow: hidden;
+}
+.res-bar > div {
+    height: 100%; width: 0%;
+    background: linear-gradient(90deg, var(--brass-lo), var(--brass-hi));
+    transition: width 0.4s ease;
+}
+.res-sub {
+    display: flex; justify-content: space-between;
+    margin-top: 6px;
+    font-size: 11px; color: var(--text-muted);
+}
+.res-sub strong {
+    color: var(--text); font-family: "SF Mono", Consolas, monospace;
+    font-weight: 500; margin-left: 4px;
+}
+
+/* Collapsible cards (h2 click toggles) */
+.card.collapsible .collapsible-toggle {
+    cursor: pointer;
+    user-select: none;
+    display: flex; align-items: center; gap: 8px;
+}
+.card.collapsible .caret {
+    display: inline-block;
+    transition: transform 0.2s ease;
+    color: var(--brass);
+    font-size: 12px;
+}
+.card.collapsible:not(.expanded) .caret { transform: rotate(-90deg); }
+.card.collapsible:not(.expanded) .card-body { display: none; }
+.card.collapsible:not(.expanded) h2 { margin: 0; }
+
+/* Server settings modal */
+.settings-grid {
+    display: grid;
+    grid-template-columns: 1fr 1fr;
+    gap: 10px;
+    margin-bottom: 14px;
+}
+.settings-grid label {
+    display: flex; flex-direction: column; gap: 4px;
+    font-size: 11px; color: var(--text-muted);
+}
+.settings-grid input, .settings-grid select {
+    background: var(--bg-deep);
+    border: 1px solid var(--card-edge);
+    border-radius: 4px;
+    color: var(--text);
+    padding: 6px 8px;
+    font-family: "SF Mono", Consolas, monospace;
+    font-size: 12px;
+}
+.settings-grid input:focus, .settings-grid select:focus {
+    outline: none; border-color: var(--brass);
+}
+.settings-grid label:nth-child(1) { grid-column: 1 / -1; } /* MOTD spans both cols */
+.settings-checks {
+    display: grid;
+    grid-template-columns: 1fr 1fr;
+    gap: 6px 14px;
+    padding-top: 10px;
+    border-top: 1px solid var(--card-edge);
+}
+.settings-checks label { font-size: 12px; }
+
+/* Whitelist requests */
+.wl-req-label {
+    font-size: 10px; letter-spacing: 0.06em; text-transform: uppercase;
+    color: var(--brass-hi); font-weight: 600;
+    margin: 6px 0 6px 2px;
+}
+#wlRequests li {
+    flex-direction: column; align-items: stretch; gap: 6px;
+}
+.wl-req-meta { font-size: 11px; color: var(--text); }
+.wl-req-msg { font-size: 11px; color: var(--text-muted); font-style: italic; }
+.wl-req-actions { display: flex; gap: 4px; }
+.wl-req-actions button { padding: 3px 8px; font-size: 10px; }
+.card h2 .badge { vertical-align: middle; margin-left: 6px; }
+
+/* Backups card */
+.backup-item {
+    display: flex; justify-content: space-between; align-items: center;
+    gap: 8px; padding: 8px 10px;
+    flex-wrap: wrap;
+}
+.backup-meta { flex: 1; min-width: 0; }
+.backup-name {
+    font-family: "SF Mono", Consolas, monospace; font-size: 11px;
+    color: var(--text); word-break: break-all;
+}
+.backup-sub { font-size: 10px; color: var(--text-muted); margin-top: 2px; }
+.backup-actions { display: flex; gap: 4px; flex-shrink: 0; }
+.backup-actions button { font-size: 10px; padding: 3px 8px; }
+
+/* Danger zone card */
+.danger-card { border-color: #6a2814; }
+.danger-card .collapsible-toggle .caret { color: var(--danger); }
+.danger-card h2 { color: #d65a3e; }
+.danger-note {
+    font-size: 12px; color: var(--text-muted);
+    margin: 0 0 12px; line-height: 1.45;
+}
+.danger-note code {
+    background: var(--bg-deep); border: 1px solid var(--card-edge);
+    padding: 1px 5px; border-radius: 3px; font-size: 11px;
+}
+.danger-row {
+    display: flex; align-items: center; gap: 8px;
+    font-size: 13px; color: var(--text);
+    cursor: pointer;
+}
+.danger-row input[type="checkbox"] { margin: 0; }
+.danger-section {
+    margin-top: 12px;
+    padding: 10px 12px;
+    border: 1px solid var(--card-edge);
+    border-radius: 6px;
+    background: rgba(255, 255, 255, 0.02);
+}
+.danger-section-title {
+    font-size: 12px; font-weight: 600;
+    text-transform: uppercase;
+    color: var(--muted);
+    margin-bottom: 8px;
+    letter-spacing: 0.4px;
+}
+.danger-section .danger-row { margin: 4px 0; }
+.danger-section code {
+    font-family: var(--mono, monospace);
+    font-size: 12px;
+    color: var(--accent, #d4a24c);
+}
+.danger-section input[type="text"] {
+    background: var(--input-bg, #0b1220);
+    color: var(--text);
+    border: 1px solid var(--card-edge);
+    border-radius: 4px;
+    padding: 4px 6px;
+    font-size: 12px;
+    font-family: var(--mono, monospace);
+}
+.danger-section input[type="text"]:disabled { opacity: 0.4; }
+
+/* Pre-generation status panel */
+.pg-status {
+    margin-top: 14px;
+    padding-top: 12px;
+    border-top: 1px solid var(--card-edge);
+    font-size: 12px;
+}
+.pg-status .stat-row { font-size: 12px; margin: 4px 0; }
+.pg-progress-bar {
+    height: 6px;
+    background: var(--bg-deep);
+    border: 1px solid var(--card-edge);
+    border-radius: 3px;
+    margin: 8px 0 10px;
+    overflow: hidden;
+}
+.pg-progress-bar > div {
+    height: 100%;
+    background: linear-gradient(90deg, var(--brass-lo), var(--brass-hi));
+    width: 0%;
+    transition: width 0.4s ease;
+}
+.pg-state-running  { color: var(--ok); }
+.pg-state-paused   { color: var(--brass-hi); }
+.pg-state-idle     { color: var(--text-muted); }
+.pg-state-cancelling { color: var(--danger); }