export type SettingValue = string | number | boolean;
export type SettingsDescriptor = Record<string, SettingValue>;
export interface AppSettingsApi<T extends SettingsDescriptor> {
    /** Current settings snapshot. */
    settings: T;
    /** Update a single setting. Emits `ui:action`. */
    set: <K extends keyof T & string>(key: K, value: T[K]) => void;
    /** Reset all settings to defaults. */
    reset: () => void;
}
/**
 * Hook for app-level persistent settings.
 *
 * @param appId  — the registry app id (must be stable across refreshes)
 * @param defaults — the settings descriptor (keys + default values)
 *
 * @example
 * ```tsx
 * const { settings, set } = useAppSettings('DisplaySettings', {
 *   wallpaper: 'bliss',
 *   screensaver: 'none',
 * });
 * set('wallpaper', 'hills');  // persists + emits ui:action
 * ```
 */
export declare function useAppSettings<T extends SettingsDescriptor>(appId: string, defaults: T): AppSettingsApi<T>;
/**
 * Read app settings from storage without a React context — used by the
 * scenario engine's `settingEquals` predicate at evaluation time.
 */
export declare function readAppSetting(storageLocal: {
    getItem: (key: string) => string | null;
}, storageKey: (shortKey: string) => string, appId: string, key: string): SettingValue | undefined;