Add Docker image, Compose, CI/CD workflows and docs

- Multi-arch (amd64/arm64) panel image: static musl binary on scratch,
  cross-compiled with cargo-zigbuild (no QEMU), non-root, healthcheck
- docker-compose.yml + .env.example for one-command deployment
- CI: fmt, clippy, tests, web type-checks, Windows launcher build,
  real-network installs of vanilla/Fabric/Quilt/Forge/NeoForge,
  Docker build
- Release: Windows NSIS installer with baked-in panel URL, GHCR image
  push and GitHub release (tag push or manual dispatch)
- README, admin guide, Microsoft auth setup, architecture, development
- rustfmt config and formatting pass

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011ARcGWxLx21FwXJ3yfGriS

crates/core/src/assets.rs

@@ -33,8 +33,7 @@ pub fn object_path(layout: &Layout, hash: &str) -> PathBuf {
 pub async fn load_index(client: &reqwest::Client, layout: &Layout, index: &AssetIndexRef) -> Result<AssetIndex> {
     let path = layout.assets().join("indexes").join(format!("{}.json", index.id));
     if !http::file_ok(&path, index.sha1.as_deref(), index.size, true) {
-        http::download_one(client, &Download::new(index.url.clone(), path.clone(), index.sha1.clone(), index.size), &|_| {})
-            .await?;
+        http::download_one(client, &Download::new(index.url.clone(), path.clone(), index.sha1.clone(), index.size), &|_| {}).await?;
     }
     Ok(serde_json::from_slice(&std::fs::read(&path)?)?)
 }
@@ -64,11 +63,7 @@ pub fn materialize_legacy(layout: &Layout, index_id: &str, index: &AssetIndex, g
     if !index.is_virtual && !index.map_to_resources {
         return Ok(None);
     }
-    let target = if index.map_to_resources {
-        game_dir.join("resources")
-    } else {
-        layout.assets().join("virtual").join(index_id)
-    };
+    let target = if index.map_to_resources { game_dir.join("resources") } else { layout.assets().join("virtual").join(index_id) };
     for (name, obj) in &index.objects {
         let Some(dest) = crate::paths::safe_join(&target, name) else { continue };
         if dest.exists() {