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>

server/cmd/api/main.go

@@ -296,7 +296,7 @@ func main() {
 	toolService := service.NewToolService(toolRepo)
 	mcpService := service.NewMCPService(mcpRepo)
 	skillService := service.NewSkillService(skillRepo)
-	agentService := service.NewAgentService(cfg.PythonServiceURL)
+	agentService := service.NewAgentService(cfg.PythonServiceURL, modelRepo)
 	memoryService := service.NewMemoryService(agentRepo)
 
 	// 4.2 初始化默认工具