{"status":"ok","service":"email-storage-server","emailCount":129,"auth":"API key required (X-API-Key header or ?key= param)","endpoints":["POST   /emails       — Nhận email mới","GET    /emails       — Danh sách email (?to=, ?limit=, ?offset=)","GET    /emails/:id   — Chi tiết 1 email","GET    /otp?email=   — Lấy OTP mới nhất (cho OTPWatcher)","DELETE /emails/:id   — Xóa 1 email","DELETE /emails       — Xóa tất cả","GET    /stats        — Thống kê"]}