Minimal shape of a node:worker_threads Worker as used by this host.
postMessage(value: unknown): void
Posts a structured-clonable message to the worker.
on(event: "message" | "error" | "exit",listener: (arg: unknown) => void): unknown
Registers an event listener ('message' payloads arrive unwrapped;
'exit' receives the numeric exit code).
terminate(): Promise<number>
Terminates the worker; resolves with the exit code.