Fix CORS: Load .env file in main.py

- Added dotenv load_dotenv() at startup to ensure ALLOWED_ORIGINS env var is loaded
- This fixes CORS errors when accessing from https://pounce.ch

backend/app/main.py

@@ -2,6 +2,10 @@
 import logging
 import os
 from contextlib import asynccontextmanager
+from dotenv import load_dotenv
+
+# Load .env file before anything else
+load_dotenv()
 
 from fastapi import FastAPI, Request, status
 from fastapi.middleware.cors import CORSMiddleware