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/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; }
+}