feat: Agent 服务日志功能和后端更新

- agent/main.py: 添加日志记录功能
- agent/llm: 更新 anthropic, openai, factory
- agent/core/agent.py: 更新
- server: agent_handler, agent_service, chat_service 更新

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

agent/app/agent/llm/factory.py

@@ -1,7 +1,7 @@
 """
 LLM Factory - LLM 工厂类
 """
-from typing import Dict, Any
+from typing import Optional
 from app.agent.llm.openai import OpenAILLM
 from app.agent.llm.anthropic import AnthropicLLM
 
@@ -10,21 +10,23 @@ class LLMFactory:
     """LLM 工厂类"""
 
     @staticmethod
-    def create(provider: str, model_name: str):
+    def create(provider: str, model_name: str, api_key: Optional[str] = None, base_url: Optional[str] = None):
         """
         创建 LLM 实例
 
         Args:
             provider: 模型提供商 (openai/anthropic)
             model_name: 模型名称
+            api_key: API Key（可选）
+            base_url: Base URL（可选）
 
         Returns:
             LLM 实例
         """
         if provider.lower() == "openai":
-            return OpenAILLM(model_name)
+            return OpenAILLM(model_name, api_key, base_url)
         elif provider.lower() == "anthropic":
-            return AnthropicLLM(model_name)
+            return AnthropicLLM(model_name, api_key)
         else:
             # 默认使用 OpenAI
-            return OpenAILLM(model_name)
+            return OpenAILLM(model_name, api_key, base_url)