/**
 * The one place a thrown value is turned into a developer-facing message.
 *
 * Five copies of this logic drifted apart across the composables and stores
 * (some checked a bare `{ message }` object, some did not); this export is the
 * union of what they all accepted, so every caller now reads the same message
 * from the same value.
 */
export declare function readErrorMessage(value: unknown, fallback?: string): string;