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.

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
+        }
+    }
+}