feat(watchers): Integrate chokidar-based Node watcher, expose awaitWriteFinish options, and update docs/tests

test/test.stress.ts

@@ -44,6 +44,8 @@ tap.test('setup: start watcher', async () => {
   testSmartwatch = new smartwatch.Smartwatch([`${TEST_DIR}/**/*.txt`]);
   await testSmartwatch.start();
   expect(testSmartwatch.status).toEqual('watching');
+  // Wait for chokidar to be ready
+  await delay(500);
 });
 
 tap.test('STRESS: rapid file modifications', async () => {