import type { SnapshotPolicy } from './policy.js';
export interface SnapshotMeta {
    readonly version: string;
    readonly label?: string;
    readonly note?: string;
    readonly exportedAt: string;
    readonly exportedBy: string;
    readonly size: number;
    /**
     * `'verified'` — bundle was produced by `writePod(vault, {})`, which embeds
     * ledgerHead metadata; `vault.load()` runs `verifyBackupIntegrity()` on restore.
     * `'legacy-unverifiable'` — reserved for v2 import paths that read pre-existing bundles
     * lacking a ledgerHead; not produced by the current engine.
     */
    readonly integrity: 'verified' | 'legacy-unverifiable';
    /** `true` for the rolling auto-snapshot; absent on on-demand checkpoints. */
    readonly auto?: true;
}
export interface RetentionPolicy {
    readonly keepLast?: number;
    readonly maxAgeDays?: number;
    readonly prune?: boolean;
}
/** @internal */
export interface SnapshotIndex {
    snapshots: SnapshotMeta[];
    nextCounter: number;
    /** Single rolling auto-snapshot slot, separate from the immutable `snapshots` pool. */
    auto?: SnapshotMeta;
}
/** @internal */
export interface SnapshotStrategy {
    snapshot(vault: unknown, by: string, opts?: {
        label?: string;
        note?: string;
    }): Promise<SnapshotMeta>;
    listSnapshots(vaultId: string): Promise<SnapshotMeta[]>;
    restoreSnapshot(vault: unknown, version: string): Promise<void>;
    /** Rolling auto-snapshot to the fixed `<vault>__auto` key. */
    autoSnapshot(vault: unknown, by: string, opts?: {
        label?: string;
        note?: string;
    }): Promise<SnapshotMeta>;
    /** Configured cadence policy. Undefined or `mode:'manual'` ⇒ no scheduler is wired. */
    readonly policy?: SnapshotPolicy;
}
/** No-op stub. @internal */
export declare const NO_SNAPSHOTS: SnapshotStrategy;