🌐 Fix CORS configuration for Synology deployment

- Add CORS_ORIGINS environment variable support in config.py
- Update main.py to properly parse CORS_ORIGINS (support both wildcard * and comma-separated URLs)
- Enable wildcard CORS for production deployment
- Fix Preflight CORS errors in browser

Resolves: CORS 400 Bad Request errors during API calls
Tested: Successfully deployed and working on Synology NAS

backend/src/main.py

@@ -34,10 +34,18 @@ app = FastAPI(
     redoc_url="/redoc"
 )
 
-# CORS 설정
+# CORS 설정 - 환경변수 처리
+cors_origins = []
+if settings.CORS_ORIGINS == "*":
+    cors_origins = ["*"]
+else:
+    cors_origins = [origin.strip() for origin in settings.CORS_ORIGINS.split(",")]
+
+logger.info(f"🌐 CORS Origins: {cors_origins}")
+
 app.add_middleware(
     CORSMiddleware,
-    allow_origins=settings.ALLOWED_ORIGINS,
+    allow_origins=cors_origins,
     allow_credentials=True,
     allow_methods=["*"],
     allow_headers=["*"],