feat(session): add session list API

- Move token-related functions from auth.go to new session.go
- Add session tracking with expiration and cleanup
- Implement session list API endpoint
- Update login/logout handlers to use session system
- Add hourly cleanup of expired tokens and sessions

router.go

@@ -15,6 +15,9 @@ func setupRoutes() {
 	http.HandleFunc("/userMgr/create", CreateUserHandler)
 	http.HandleFunc("/userMgr/remove", RemoveUserHandler)
 	http.HandleFunc("/userMgr/list", ListUserHandler)
+	// http.HandleFunc("/userMgr/modify", ModifyUserHandler)
+
+	http.HandleFunc("/sessionMgr/list", ListActiveSessionsHandler)
 
 	http.HandleFunc("/frpcAct/instanceMgr/create", CreateInstanceHandler)
 	http.HandleFunc("/frpcAct/instanceMgr/list", ListInstancesHandler)