/**
 * Persistence helpers for per-principal user envelopes stored at
 * `_users/<keyringId>` (logically: `_meta/user/<keyringId>`).
 *
 * Unlike `_meta/policy` and `_meta/handle` which are plaintext, user
 * envelopes carry user data and are encrypted with a dedicated
 * {@link USER_ENVELOPE_COLLECTION} DEK (provisioned at vault open and
 * propagated to every keyring via the system-collection DEK path in
 * `team/keyring.ts`).
 *
 * This module is the **storage primitive** layer. The public API
 * (`vault.user.*`) sits on top of this; permission gates, own-only
 * write enforcement, and presence-channel propagation live there.
 *
 * @see docs/superpowers/specs/2026-05-05-user-envelope-design.md
 *
 * @module
 */
import type { NoydbStore, UserEnvelope } from '../../../kernel/types.js';
import { type EnclaveKey } from '../../../kernel/enclave/index.js';
/**
 * Read and decrypt the user envelope for `keyringId`. Returns `null`
 * when no envelope has been persisted (either the principal has never
 * called `updateMe`, or the keyring predates this feature).
 *
 * Decryption errors propagate — a tampered or wrong-keyed envelope
 * surfaces as the underlying crypto error rather than masquerading as
 * "not found".
 */
export declare function loadUserEnvelope<T = unknown>(store: NoydbStore, vault: string, keyringId: string, dek: EnclaveKey): Promise<UserEnvelope<T> | null>;
/**
 * Encrypt and persist the user envelope for `keyringId`. The new
 * version is `(prior._v ?? 0) + 1`. Pass `expectedVersion` to enable
 * optimistic-concurrency checks: a mismatch with the stored version
 * throws {@link ConflictError} with the actual stored version.
 *
 * `expectedVersion: 0` means "expect no prior envelope"; the write
 * succeeds only if no envelope exists yet.
 *
 * Soft-caps the JSON-serialized payload at {@link USER_ENVELOPE_MAX_BYTES};
 * larger payloads throw {@link UserEnvelopeOversizedError}.
 */
export declare function saveUserEnvelope<T>(store: NoydbStore, vault: string, keyringId: string, payload: T, dek: EnclaveKey, expectedVersion?: number): Promise<UserEnvelope<T>>;
/**
 * Delete the user envelope for `keyringId`. Idempotent — no error if
 * the envelope is already absent. Called from the keyring revoke path
 * (cascade-delete) and is a no-op for keyrings that never wrote.
 */
export declare function deleteUserEnvelope(store: NoydbStore, vault: string, keyringId: string): Promise<void>;
/**
 * List the keyring ids that have a user envelope persisted in `vault`.
 * Order is store-defined — callers that need a stable order should sort.
 */
export declare function listUserEnvelopeIds(store: NoydbStore, vault: string): Promise<string[]>;