/**
 * Cross-tick GitHub API response cache — reduces redundant requests across
 * `pr-shepherd` poll ticks.
 *
 * Two entry kinds, both keyed by a caller-chosen logical `name` (hashed to a
 * filesystem-safe filename, mirroring seen-comments.mts):
 *
 * - "etag" entries back conditional REST requests (`If-None-Match`). A 200
 *   response overwrites the entry; a 304 leaves it untouched. Used for list
 *   endpoints whose content can change from tick to tick (job lists, run
 *   lists).
 * - "derived" entries cache a value computed from a response that is
 *   immutable once identified by its key — job-log excerpts once a job is
 *   terminal, check-run annotations once the check is COMPLETED. No ETag
 *   applies; the cache is keyed on an immutable identity instead.
 *
 * Entries live under `$PR_SHEPHERD_STATE_DIR/<owner>-<repo>/<pr>/rest-cache/`
 * and are removed for free when `pr-shepherd clean` deletes the PR's state
 * directory — there is no separate pruning routine.
 */
export interface StateKey {
    owner: string;
    repo: string;
    pr: number;
}
export interface EtagCacheEntry {
    kind: "etag";
    name: string;
    etag: string;
    body: unknown;
    storedAt: number;
    headSha?: string;
}
export interface DerivedCacheEntry<T = unknown> {
    kind: "derived";
    name: string;
    value: T;
    storedAt: number;
    headSha?: string;
}
export declare function loadEtagEntry(key: StateKey, name: string): Promise<EtagCacheEntry | null>;
export declare function storeEtagEntry(key: StateKey, name: string, fields: {
    etag: string;
    body: unknown;
    headSha?: string;
}): Promise<void>;
export declare function loadDerived<T = unknown>(key: StateKey, name: string): Promise<DerivedCacheEntry<T> | null>;
export declare function storeDerived<T = unknown>(key: StateKey, name: string, value: T, headSha?: string): Promise<void>;