feat: remove all unnecessary fields in GroupMember and implement MessageEvent field for pipeline events

src/langbot/pkg/plugin/handler.py

@@ -139,6 +139,8 @@ class RuntimeConnectionHandler(handler.Handler):
 
             message_chain_obj = platform_message.MessageChain.model_validate(message_chain)
 
+            self.ap.logger.debug(f'Reply message: {message_chain_obj.model_dump(serialize_as_any=False)}')
+
             await query.adapter.reply_message(
                 query.message_event,
                 message_chain_obj,