/**
 * stale-policy — pure helper for stale detection and filtering on memory
 * and (future) retrospective entries.
 *
 * and the underlying `readMemoryIndex` load path). The retrospective index
 * loader shares the same shape (`updatedAt: string`) and will be wired to
 * the same helper in a future slice.
 *
 * Behavior:
 *   - `isStale(updatedAt)` returns true when (now - updatedAt) >
 *     thresholdDays * 86_400_000. Strict greater-than: a 30-day-old
 *     entry is NOT stale.
 *   - `applyStalePolicy(entries)` adds `stale: boolean` and
 *     `ageDays: number` to every entry (computed at CLI load time, never
 *     persisted to source `.md` files) and filters out entries where
 *     `stale === true` unless `includeStale: true` is passed.
 *   - Missing `updatedAt` is treated as fresh (`stale: false`,
 *     `ageDays: 0`); we never throw, so older index.json entries that
 *     lack the field stay loadable.
 */
export interface StalePolicyOptions {
    /** Reference clock (ms since epoch). Defaults to Date.now(). Injected for testability. */
    now?: number;
    /** Threshold in days. Default 30. */
    thresholdDays?: number;
    /** When true, keep stale entries in the returned array (with `stale: true` set). Default false. */
    includeStale?: boolean;
}
export interface StaleAnnotated<T> {
    stale: boolean;
    ageDays: number;
}
export type StaleAnnotatedEntry<T> = T & StaleAnnotated<T>;
export interface StalePolicyResult<T> {
    /** Filtered array, with stale entries removed (unless includeStale=true). */
    entries: StaleAnnotatedEntry<T>[];
    /** Count of entries dropped as stale. */
    droppedCount: number;
    /** Total count before filtering. */
    totalCount: number;
}
export declare const DAY_MS = 86400000;
export declare const DEFAULT_STALE_DAYS = 30;
/**
 * Returns true when the entry is older than `thresholdDays`. Strict
 * greater-than: an entry exactly at the threshold is NOT stale.
 *
 * A missing or unparseable `updatedAt` is treated as fresh (false). This
 * is the "defensive — older index.json entries may lack the field" rule
 * from PRD R4.
 */
export declare function isStale(updatedAt: string | undefined | null, options?: StalePolicyOptions): boolean;
/**
 * Age in days between `updatedAt` and `now` (default Date.now()).
 * Returns 0 for a missing / unparseable `updatedAt`.
 */
export declare function ageInDays(updatedAt: string | undefined | null, now?: number): number;
/**
 * Apply the stale policy to a list of entries. Each entry is augmented
 * with `stale: boolean` and `ageDays: number` (immutably — a fresh
 * object is returned per entry). Stale entries are dropped from
 * `entries` unless `includeStale: true` is passed.
 */
export declare function applyStalePolicy<T extends {
    updatedAt?: string | null;
}>(entries: T[], options?: StalePolicyOptions): StalePolicyResult<T>;