curl -X POST "https://demo.api.vultlocal.com/api/v1/subscribers/sub_abc123/unblock" \
  -H "Authorization: Bearer olive_live_xxx"

{
  "success": true,
  "message": "Subscriber unblocked successfully",
  "unblocked_at": "2025-01-20T15:30:00Z",
  "unblocked_by": "admin@olive.sl"
}

{
  "error": "Subscriber not found",
  "code": "NOT_FOUND"
}

{
  "error": "Subscriber is not blocked",
  "code": "NOT_BLOCKED"
}