/**
 * SIGKILL this process once `parentPid` exits or this process is reparented.
 *
 * Called by `runIpcSubprocessWorker` (cli.ts) for every IPC subprocess worker.
 * Liveness is polled on a dedicated worker thread rather than the main event
 * loop: inference workers pin their main thread inside synchronous native calls
 * (onnxruntime `session.run`) for minutes at a time, and a main-loop watchdog
 * cannot fire until that call returns — leaving a multi-GiB orphan behind a
 * dead parent (issue #14340). The thread is `unref`'d; it never keeps the
 * process alive by itself.
 */
export declare function startParentWatchdog(parentPid: number): void;