Fixed an issue where file watch events were not emitted for files created immediately after creating their parent directory.

Problem

When using fs.watch() with recursive: true, files created immediately after directory creation would not trigger watch events. For example:

const { fs } = require("memfs");
const path = require("path");

const watchedDirectory = path.join(__dirname, "watched");

fs.mkdirSync(watchedDirectory, { recursive: true });
fs.watch(watchedDirectory, { recursive: true }, (eventType, filename) => {
  console.log("Received: " + eventType + " " + filename);
});

fs.mkdirSync(path.join(watchedDirectory, "new_dir"), { recursive: true });
fs.writeFileSync(path.join(watchedDirectory, "new_dir", "new_file"), "stuff");

Before fix: Only showed rename new_dir (missing the file creation event)
After fix: Shows both rename new_dir and rename new_dir/new_file

Root Cause

In src/node/volume.ts, the onLinkChildAdd function was wrapping the watcher setup calls in a setTimeout():

const onLinkChildAdd = (l: Link) => {
  this.emit('change', 'rename', relative(this._filename, l.getPath()));

  setTimeout(() => {  // <-- This was the problem
    watchLinkNodeChanged(l);
    watchLinkChildrenChanged(l);
  });
};

This deferred the setup of watchers for newly created directories to the next tick of the event loop. When files were created immediately after directory creation, the watchers weren't ready yet, causing events to be missed.

Solution

Removed the setTimeout() wrapper to make watcher setup synchronous:

const onLinkChildAdd = (l: Link) => {
  this.emit('change', 'rename', relative(this._filename, l.getPath()));

  // Set up watchers immediately
  watchLinkNodeChanged(l);
  watchLinkChildrenChanged(l);
};

Testing

• Added a focused test case that reproduces the original issue
• Updated existing tests to reflect the correct (increased) number of events now being captured
• Verified the fix works with the original reproduction case
• All existing tests continue to pass

The behavior now more closely matches Node.js's native fs.watch() implementation.

Fixes #1014.

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