feat: log provider errors to console for better insights (#23379)

* fix: log provider errors that were silently swallowed

* Update main.py

* fix: wrap non-JSON SSE error responses in JSON so middleware handles them

backend/open_webui/utils/middleware.py

@@ -3077,6 +3077,8 @@ async def non_streaming_chat_response_handler(response, ctx):
                 else:
                     error = str(error)
 
+                log.error('Provider returned error (non-streaming): %s', error)
+
                 await Chats.upsert_message_to_chat_by_id_and_message_id(
                     metadata['chat_id'],
                     metadata['message_id'],
@@ -3645,6 +3647,7 @@ async def streaming_chat_response_handler(response, ctx):
                                     if not choices:
                                         error = data.get('error', {})
                                         if error:
+                                            log.error('Provider returned error (streaming): %s', error)
                                             try:
                                                 await Chats.upsert_message_to_chat_by_id_and_message_id(
                                                     metadata['chat_id'],