debug: 添加更多调试日志来诊断 llm_token 不输出的问题

backend/app/agent/agent_service.py

@@ -218,6 +218,8 @@ class AIAgentService:
                     reasoning_token = ""
                     if hasattr(message_chunk, 'additional_kwargs'):
                         reasoning_token = message_chunk.additional_kwargs.get("reasoning_content", "")
+                    
+                    info(f"💬 消息token: token_content='{repr(token_content[:50])}', reasoning_token='{repr(reasoning_token[:50])}', node_name='{node_name}'")
 
                     # 处理思考过程
                     if reasoning_token:
@@ -226,6 +228,7 @@ class AIAgentService:
                             "node": node_name,
                             "reasoning_token": reasoning_token
                         }
+                        info(f"✅ 生成 reasoning_token 事件: {processed_event}")
                     # 处理工具调用
                     elif hasattr(message_chunk, 'tool_calls') and message_chunk.tool_calls:
                         for tool_call in message_chunk.tool_calls:
@@ -253,6 +256,9 @@ class AIAgentService:
                             "token": token_content,
                             "reasoning_token": reasoning_token
                         }
+                        info(f"✅ 生成 llm_token 事件: {processed_event}")
+                    else:
+                        info(f"⚠️ 没有生成任何事件，token_content='{repr(token_content)}', reasoning_token='{repr(reasoning_token)}'")
 
                 elif chunk_type == "updates":
                     info(f"🔄 处理updates chunk")