feat: Initial project structure for WebTriviasMulti

- Backend: FastAPI + Python-SocketIO + SQLAlchemy
  - Models for categories, questions, game sessions, events
  - AI services for answer validation and question generation (Claude)
  - Room management with Redis
  - Game logic with stealing mechanics
  - Admin API for question management

- Frontend: React + Vite + TypeScript + Tailwind
  - 5 visual themes (DRRR, Retro, Minimal, RGB, Anime 90s)
  - Real-time game with Socket.IO
  - Achievement system
  - Replay functionality
  - Sound effects per theme

- Docker Compose for deployment
- Design documentation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,12 @@
+# Backend
+DATABASE_URL=postgresql://trivia:trivia@db:5432/trivia
+REDIS_URL=redis://redis:6379
+ANTHROPIC_API_KEY=sk-ant-your-api-key
+JWT_SECRET=your-super-secret-jwt-key
+
+# Frontend
+VITE_API_URL=http://localhost:8000
+VITE_WS_URL=ws://localhost:8000
+
+# Cloudflare Tunnel
+CLOUDFLARE_TUNNEL_TOKEN=your-tunnel-token