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

docs/development.md

@@ -0,0 +1,36 @@
+# Development
+
+**Requirements:** Rust (stable), Node 22. On Linux, also the Tauri deps: `libwebkit2gtk-4.1-dev librsvg2-dev libayatana-appindicator3-dev`.
+
+## Panel
+
+```bash
+cd panel/web && npm install && npm run build && cd ../..
+ADMIN_PASSWORD=adminadmin cargo run -p scopenet-panel     # http://localhost:8080
+# UI hot reload: (cd panel/web && npm run dev)            # http://localhost:5173, proxies /api
+```
+
+## Launcher
+
+```bash
+cd launcher && npm install
+npm run tauri dev          # full desktop app
+npm run dev                # UI only in a browser, with a mock backend (http://localhost:1420)
+```
+
+Browser mock scenarios: `?mock=setup`, `?mock=login`, `?mock=progress`.
+
+Build-time options (environment variables when building): `SCOPENET_PANEL_URL`, `SCOPENET_LOCK_PANEL=1`, `SCOPENET_REPO=owner/repo`.
+
+## Tests
+
+```bash
+cargo test --workspace                                         # unit + panel API tests
+cargo test -p scopenet-core --test online -- --ignored        # real installs (needs internet, ~2 GB)
+(cd panel/web && npm run check) && (cd launcher && npm run check)
+cargo fmt --all && cargo clippy --workspace --all-targets -- -D warnings
+```
+
+## Releasing
+
+Push a tag `vX.Y.Z` or run the **Release** workflow. It stamps the version into `Cargo.toml` and `tauri.conf.json`, builds the NSIS installer on Windows, pushes the multi-arch panel image to GHCR, and publishes the release.