curl -X POST 'https://app.memorylake.cn/openapi/admin/api/v1/invitations' \
  -H 'Authorization: Bearer sk-admin-xxxxxx' \
  -H 'Content-Type: application/json' \
  -d '{"email": "bob@example.com", "role": "tenant_member"}'

{
  "success": true,
  "message": "Operation completed successfully",
  "data": {
    "id": "88",
    "email": "bob@example.com",
    "role": "tenant_member",
    "status": "pending",
    "created_at": 1756300000,
    "expires_at": 1756904800,
    "last_invited_at": 1756300000
  }
}

{
  "success": false,
  "message": "a pending invitation for this email already exists; revoke it to re-invite",
  "error_code": "CUSTOM_ID_CONFLICT"
}