{
  "type": "image",
  "key": "app_background_image_url",
  "constant": "APP_BACKGROUND_IMAGE_URL",
  "description": "Default background image URL for all users (leave empty to use theme defaults)",
  "required": false,
  "placeholder": "https://example.com/background.jpg",
  "validation": "string|max:2048",
  "options": [],
  "category": "app",
  "sensitive": false
}