node:worker_threads: implement Web Locks request and query #3328

Summary

worker_threads.locks should expose Node's experimental Web Locks manager with locks.request(), locks.query(), and Lock objects. Perry currently has no visible worker_threads Web Locks implementation.

Node Behavior

A Node v25.9.0 probe shows the local lock manager shape:

const { locks } = require("node:worker_threads");

console.log(typeof locks, typeof locks.request, typeof locks.query); // object function function
const result = await locks.request("perry-probe", async (lock) => {
  console.log(lock.constructor.name, lock.name, lock.mode); // Lock perry-probe exclusive
  const snapshot = await locks.query();
  console.log(snapshot.held.map(l => `${l.name}:${l.mode}`).join(",")); // perry-probe:exclusive
  return "done";
});
console.log(result); // done
console.log((await locks.query()).held.length); // 0

Node resolves the callback result, exposes held/pending snapshots, and surfaces Lock instances with name and mode.

Perry Behavior

docs/runtime-parity-gaps.md lists worker_threads.locks; docs/runtime-parity.md lists locks.request(name[, options], callback), locks.query(), and class Lock under worker_threads Web Locks. Source search found no worker_threads locks manager, manifest entries, or tests for this surface. Exact issue/PR searches for worker_threads.locks, locks.request, locks.query, and Web Locks found no focused tracker beyond the broad parent #2507 where Web Locks were explicitly deferred.

Suggested PR Cut

Batch this with related issues in:
node:worker_threads: Web Locks parity cut

Good batch candidates:

• node:worker_threads: worker and messaging parity cut #2507

Do not batch with:

• unrelated modules
• broad subsystem rewrites
• fixes needing different test harnesses
• MessagePort / BroadcastChannel delivery
• Worker constructor execution
• Worker heap/profile diagnostics

Acceptance

• parity/regression test proves worker_threads.locks.request() grants an exclusive lock, passes a Node-shaped Lock object to the callback, and resolves to the callback return value
• worker_threads.locks.query() exposes held and pending arrays with Node-compatible shape for covered cases
• implementation matches Node observable behavior
• related known-failure/docs/manifest entries updated if touched