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/version.rs

@@ -170,11 +170,7 @@ impl VersionJson {
     }
 
     pub fn java_component(&self) -> String {
-        self.java_version
-            .as_ref()
-            .map(|j| j.component.clone())
-            .filter(|c| !c.is_empty())
-            .unwrap_or_else(|| "jre-legacy".into())
+        self.java_version.as_ref().map(|j| j.component.clone()).filter(|c| !c.is_empty()).unwrap_or_else(|| "jre-legacy".into())
     }
 
     /// True for 1.13+ style argument lists.