/**
 * Persistence helpers for the per-user visibility flag
 * (`_meta/visibility/<keyringId>`). Mirrors the bypass-AES pattern used
 * by `_meta/policy` — the visibility document is plain JSON, the
 * envelope's `_iv` field is left empty.
 *
 * Stored alongside the keyring file rather than inside the encrypted
 * user envelope (`_users/<keyringId>`) because:
 *
 *  - `UserEnvelope<T>.data` is opaque-to-hub by contract — hub does not
 *    introspect or reserve any keys inside it. Adding `hidden` there
 *    would violate that contract.
 *  - `listUsersWithEnvelopes` filters by the flag, and the filter must
 *    work even when decryption fails (legacy keyrings predating the
 *    envelope feature, or a corrupted envelope).
 *
 * @see https://github.com/vLannaAi/noy-db-docs/blob/main/content/docs/services/user-envelope.md → Directory visibility
 * @see https://github.com/vLannaAi/noy-db-docs/blob/main/content/docs/services/plaintext-bypass.md — every `_iv: ''` write site
 *
 * @module
 */
import type { NoydbStore } from '../../kernel/types.js';
import type { UserVisibility } from './types.js';
/** Prefix for per-user visibility records inside `_meta`. */
export declare const VISIBILITY_RECORD_PREFIX = "visibility/";
/** Compose the `_meta` record id for a keyring's visibility doc. */
export declare function visibilityRecordId(keyringId: string): string;
/**
 * Read the visibility flag for `keyringId`. Returns `undefined` when no
 * document has been persisted — callers treat that as the default-visible
 * case (`{ hidden: false }`).
 */
export declare function readUserVisibility(store: NoydbStore, vault: string, keyringId: string): Promise<UserVisibility | undefined>;
/**
 * Persist the visibility flag for `keyringId` at
 * `_meta/visibility/<keyringId>`. Idempotent — call on every
 * `vault.user.setMyVisibility()` invocation. Own-only at the caller
 * site; this primitive does not enforce keyring ownership.
 */
export declare function persistUserVisibility(store: NoydbStore, vault: string, keyringId: string, visibility: UserVisibility): Promise<void>;
/**
 * Delete the visibility flag for `keyringId`. Called from `revoke()`
 * alongside `deleteUserEnvelope` so the sidecar does not leak to a
 * re-granted principal with the same `userId`. Idempotent — the store's
 * `delete()` is already a no-op when the record is absent.
 */
export declare function deleteUserVisibility(store: NoydbStore, vault: string, keyringId: string): Promise<void>;