Initial commit: Gaming Hub foundation

Plugin-based Discord bot framework with web frontend:
- Core: Discord.js client, SSE broadcast, JSON persistence
- Plugin system: lifecycle hooks (init, onReady, routes, snapshot, destroy)
- Web: React 19 + Vite 6 + TypeScript, tab-based navigation
- Docker: multi-stage build (Node 24, static ffmpeg, yt-dlp)
- GitLab CI: Kaniko with LAN registry caching

Ready for plugin development.

web/src/main.tsx

@@ -0,0 +1,5 @@
+import { createRoot } from 'react-dom/client';
+import App from './App';
+import './styles.css';
+
+createRoot(document.getElementById('root')!).render(<App />);