fix(subscription): add default value for total

Author: x0sina

app/operation/subscription.py

@@ -68,7 +68,7 @@ def _format_profile_title(
     def create_response_headers(user: UsersResponseWithInbounds, request_url: str, sub_settings: SubSettings) -> dict:
         """Create response headers for subscription responses, including user subscription info."""
         # Generate user subscription info
-        user_info = {"upload": 0, "download": user.used_traffic, "expire": 0}
+        user_info = {"upload": 0, "download": user.used_traffic, "total": 0, "expire": 0}
 
         if user.data_limit:
             user_info["total"] = user.data_limit