fix: reduce task startup overhead and lazy-load notifications (#3080)

test/back/node-path-cache.test.cjs

@@ -65,6 +65,35 @@ test('config, environment, cwd, and executable changes invalidate discovery', (t
   f.run();
   assert.equal(f.count(), before + 1);
 });
+test('alternating Node/crond working directories retain independent cached roots', (t) => {
+  const f = fixture(t);
+  fs.mkdirSync(path.join(f.root, 'child'));
+  fs.writeFileSync(path.join(f.root, 'child', '.npmrc'), 'global-dir=/child\n');
+  for (let i = 0; i < 4; i++) {
+    assert.equal(f.run({ ANSWER: '/parent/modules' }).stdout.trim(), '/parent/modules');
+    assert.equal(
+      f.run({ ANSWER: '/child/modules' }, 'cd child; ' + f.command).stdout.trim(),
+      '/child/modules',
+    );
+  }
+  assert.equal(f.count(), 2, 'each working directory should discover only once');
+  assert.equal(fs.readdirSync(f.env.dir_tmp).filter((x) => x.endsWith('.cache')).length, 2);
+});
+test('refresh retires old per-environment records without removing locks or unrelated files', (t) => {
+  const f = fixture(t);
+  fs.mkdirSync(f.env.dir_tmp);
+  const prefix = `pnpm-root-${process.getuid()}`;
+  const names = [`${prefix}-1-2.cache`, `${prefix}.lock`, 'unrelated.cache'];
+  const old = new Date(Date.now() - 2 * 60 * 60 * 1000);
+  for (const name of names) {
+    const file = path.join(f.env.dir_tmp, name);
+    fs.writeFileSync(file, '');
+    fs.utimesSync(file, old, old);
+  }
+  assert.equal(f.run().status, 0);
+  assert.equal(fs.existsSync(path.join(f.env.dir_tmp, names[0])), false);
+  for (const name of names.slice(1)) assert.ok(fs.existsSync(path.join(f.env.dir_tmp, name)));
+});
 test('expired or malformed records refresh and failed lookups are not cached', (t) => {
   const f = fixture(t);
   f.run();