feat: 增强会话管理和 Agent 服务

- 优化 session_handler 会话处理逻辑
- 增强 agent_service Agent 服务功能
- 新增 chat_repository 仓储方法
- 更新 agent_handler 和 chat_group_handler
- 更新数据模型 agent 和 chat_session

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

server/cmd/api/main.go

@@ -377,7 +377,7 @@ func main() {
 	toolService := service.NewToolService(toolRepo)
 	mcpService := service.NewMCPService(mcpRepo)
 	skillService := service.NewSkillService(skillRepo)
-	agentService := service.NewAgentService(cfg.PythonServiceURL, modelRepo, agentRepo)
+	agentService := service.NewAgentService(cfg.PythonServiceURL, modelRepo, agentRepo, chatRepo)
 	memoryService := service.NewMemoryService(agentRepo)
 
 	// 4.2 初始化默认工具
@@ -407,7 +407,7 @@ func main() {
 	skillHandler := handler.NewSkillHandler(skillService)
 	agentHandler := handler.NewAgentHandler(agentService)
 	memoryHandler := handler.NewMemoryHandler(memoryService)
-	sessionHandler := handler.NewSessionHandler(chatRepo)
+	sessionHandler := handler.NewSessionHandler(chatRepo, agentService)
 
 	// 初始化群聊服务
 	chatGroupRepo := repository.NewChatGroupRepository(db)
@@ -608,6 +608,7 @@ func main() {
 		chatGroup.DELETE("/sessions/:id", sessionHandler.DeleteSession)
 		chatGroup.GET("/sessions/:id/messages", sessionHandler.GetMessages)
 		chatGroup.POST("/messages", sessionHandler.CreateMessage)
+		chatGroup.POST("/sessions/generate-title", sessionHandler.GenerateSessionTitle)
 	}
 
 	// 群聊管理模块