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/java.rs

@@ -86,7 +86,11 @@ pub fn sibling_exe(java: &Path, windowed: bool) -> PathBuf {
     }
     let name = if windowed { "javaw.exe" } else { "java.exe" };
     let candidate = java.with_file_name(name);
-    if candidate.exists() { candidate } else { java.to_path_buf() }
+    if candidate.exists() {
+        candidate
+    } else {
+        java.to_path_buf()
+    }
 }
 
 /// Make sure the Mojang runtime `component` (e.g. `java-runtime-delta`) is
@@ -102,15 +106,14 @@ pub async fn ensure_runtime(
     let marker = dir.join(".scopenet-runtime");
     let installed = std::fs::read_to_string(&marker).ok();
 
-    let index: HashMap<String, HashMap<String, Vec<RuntimeEntry>>> =
-        match http::get_json(client, RUNTIME_INDEX).await {
-            Ok(i) => i,
-            Err(e) if installed.is_some() && java_exe(&dir, false).exists() => {
-                tracing::warn!("java index unreachable ({e}); using installed {component}");
-                return Ok(dir);
-            }
-            Err(e) => return Err(e).context("fetching Java runtime index"),
-        };
+    let index: HashMap<String, HashMap<String, Vec<RuntimeEntry>>> = match http::get_json(client, RUNTIME_INDEX).await {
+        Ok(i) => i,
+        Err(e) if installed.is_some() && java_exe(&dir, false).exists() => {
+            tracing::warn!("java index unreachable ({e}); using installed {component}");
+            return Ok(dir);
+        }
+        Err(e) => return Err(e).context("fetching Java runtime index"),
+    };
     let entry = index
         .get(platform_key())
         .and_then(|p| p.get(component))
@@ -188,7 +191,11 @@ pub fn parse_java_version(text: &str) -> Option<u32> {
     let ver = &rest[..rest.find('"')?];
     let mut parts = ver.split(['.', '_', '-', '+']);
     let first: u32 = parts.next()?.parse().ok()?;
-    if first == 1 { parts.next()?.parse().ok() } else { Some(first) }
+    if first == 1 {
+        parts.next()?.parse().ok()
+    } else {
+        Some(first)
+    }
 }
 
 #[cfg(test)]