/**
 * Compute a stable offline storage key to use for local/demo mode.
 *
 * Defaults to `"noya-local"` when no fileId is provided. A custom namespace
 * can be supplied to avoid collisions across app contexts.
 */
export function getOfflineStorageKey(
  fileId?: string,
  namespace?: string
): string {
  if (fileId && fileId.length > 0) return fileId;
  return namespace ? `${namespace}-local` : "noya-local";
}