{"status":"success","message":"體育客 GymSaaS Backend API（前後端分離｜本服務不提供 UI）","data":{"health":"/api/health","websocket":["/ws/occupancy","/ws/gate-alert"],"docsNote":"請由獨立前端網域（FRONTEND_URL，例如 https://app.firstfittw.com）呼叫本 API；FRONTEND_URL 僅用於 OAuth／金流瀏覽器回流，禁止與 API_PUBLIC_URL 同網域"}}