Fix syntax error on line 729 - unterminated f-string and missing bracket

app.py

@@ -726,7 +726,9 @@ async def download_video_models():
         if free_gb < 10:  # Need at least 10GB free
             return {
                 "success": False,
-                "message": f"Insufficient storage: {free_gb:.1f}
+                "message": f"Insufficient storage: {free_gb:.1f}GB available, need at least 10GB for model download",
+            }
+
 @app.post("/reload-models")
 async def reload_models():
     """Force reload model detection after download"""