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>

backend/app/models/__init__.py

@@ -0,0 +1,7 @@
+from app.models.category import Category
+from app.models.question import Question
+from app.models.game_session import GameSession
+from app.models.game_event import GameEvent
+from app.models.admin import Admin
+
+__all__ = ["Category", "Question", "GameSession", "GameEvent", "Admin"]