Fix security

backend/app/main.py

@@ -1,7 +1,10 @@
 import logging
 from contextlib import asynccontextmanager
 
-from fastapi import FastAPI
+from fastapi import FastAPI, Request
+from fastapi.responses import JSONResponse
+from slowapi import _rate_limit_exceeded_handler
+from slowapi.errors import RateLimitExceeded
 
 # Configure logging
 logging.basicConfig(
@@ -14,6 +17,7 @@ from pathlib import Path
 
 from app.core.config import settings
 from app.core.database import engine, Base, async_session_maker
+from app.core.rate_limit import limiter
 from app.api.v1 import router as api_router
 from app.services.event_scheduler import event_scheduler
 from app.services.dispute_scheduler import dispute_scheduler
@@ -49,6 +53,10 @@ app = FastAPI(
     lifespan=lifespan,
 )
 
+# Rate limiting
+app.state.limiter = limiter
+app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)
+
 # CORS
 app.add_middleware(
     CORSMiddleware,