Create Admin

POST /admins

{
  "fullname": "New Admin",
  "email": "[email protected]",
  "password": "securepassword123",
  "isActive": true
}

{
  "success": true,
  "data": {
    "id": "uuid",
    "fullname": "New Admin",
    "email": "[email protected]",
    "isActive": true
  }
}