/** 手写 semver 比较（零依赖，假设纯数字 x.y.z，非数字段 fallback 0）。返回 -1/0/1。 */
export declare function compareVersion(a: string, b: string): number;
interface CacheData {
    lastCheck: number;
    latest: string;
}
export declare function readCache(cachePath: string): CacheData | null;
export interface UpdateCheckResult {
    current: string;
    latest: string;
    updateAvailable: boolean;
    fromCache: boolean;
}
/** 查 npm 最新版。force:true 绕缓存（供 check action）；cacheDir 测试注入。失败绝不抛。 */
export declare function checkForUpdateCached(opts?: {
    force?: boolean;
    cacheDir?: string;
}): Promise<UpdateCheckResult>;
export {};