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.

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()));
+}