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/main.py

@@ -0,0 +1,76 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+import socketio
+from contextlib import asynccontextmanager
+
+from app.config import get_settings
+from app.api import admin, game, replay
+from app.sockets.game_events import register_socket_events
+
+settings = get_settings()
+
+# Socket.IO server
+sio = socketio.AsyncServer(
+    async_mode="asgi",
+    cors_allowed_origins="*",
+    logger=True,
+    engineio_logger=True
+)
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    # Startup
+    print("Starting WebTriviasMulti server...")
+    yield
+    # Shutdown
+    print("Shutting down WebTriviasMulti server...")
+
+
+# FastAPI app
+app = FastAPI(
+    title="WebTriviasMulti API",
+    description="API para el juego de trivia multiplayer",
+    version="1.0.0",
+    lifespan=lifespan
+)
+
+# CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include routers
+app.include_router(admin.router, prefix="/api/admin", tags=["admin"])
+app.include_router(game.router, prefix="/api/game", tags=["game"])
+app.include_router(replay.router, prefix="/api/replay", tags=["replay"])
+
+# Register Socket.IO events
+register_socket_events(sio)
+
+# Mount Socket.IO
+socket_app = socketio.ASGIApp(sio, app)
+
+
+@app.get("/")
+async def root():
+    return {
+        "message": "WebTriviasMulti API",
+        "version": "1.0.0",
+        "status": "running"
+    }
+
+
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy"}
+
+
+# For running with uvicorn directly
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run("app.main:socket_app", host="0.0.0.0", port=8000, reload=True)