feat: add rate limiting, CORS, queue loop in lifespan

src/backend/main.py

@@ -1,21 +1,55 @@
+import asyncio
+import logging
 from contextlib import asynccontextmanager
 
 from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from slowapi import _rate_limit_exceeded_handler
+from slowapi.errors import RateLimitExceeded
 
+from src.backend.api.dependencies import limiter
 from src.backend.api.routes.health import router as health_router
-from src.backend.api.routes.topics import router as topics_router
 from src.backend.api.routes.requests import router as requests_router
 from src.backend.api.routes.sessions import router as sessions_router
+from src.backend.api.routes.topics import router as topics_router
 from src.backend.db.database import init_db
+from src.backend.services.queue import queue_loop
+from src.backend.services.worker_client import WorkerClient
+
+logging.basicConfig(level=logging.INFO)
 
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     await init_db()
+    worker = WorkerClient()
+    task = asyncio.create_task(queue_loop(worker))
     yield
+    task.cancel()
+    try:
+        await task
+    except asyncio.CancelledError:
+        pass
 
 
-app = FastAPI(title="OpusAgent", version="0.1.0", lifespan=lifespan)
+app = FastAPI(
+    title="OpusAgent",
+    version="0.1.0",
+    docs_url="/doc",
+    redoc_url="/redoc",
+    openapi_url="/openapi.json",
+    lifespan=lifespan,
+)
+
+app.state.limiter = limiter
+app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
 
 app.include_router(health_router, prefix="/api")
 app.include_router(topics_router, prefix="/api")