export type SelfUpgradeWatchOptions = {
    cwd: string;
    port: number;
    hostname: string;
    /** Currently-loaded version to compare against — defaults to PLUGIN_VERSION, overridable for tests. */
    currentVersion: string;
    checkIntervalMs?: number;
    /** Injectable for tests — defaults to spawning a real detached `serve` re-invocation. */
    onNewerVersionDetected?: (installedVersion: string) => void;
};
/** Re-reads the installed package.json fresh off disk — never the require-cached copy. */
export declare function readInstalledVersion(): string;
/**
 * Registers a periodic check; returns an unregister function (clears the
 * interval). Stops itself after the first detected mismatch — only ever
 * triggers one respawn per process.
 */
export declare function registerSelfUpgradeWatch(opts: SelfUpgradeWatchOptions): () => void;