feat(qmd): warm the index and daemon from a SessionStart hook

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/tests/test-qmd-warm.mjs

@@ -0,0 +1,25 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { mkdtempSync, writeFileSync, existsSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { withLock } from '../../shared/qmd/qmd-warm.mjs';
+
+test('a fresh lock skips the second warm-up and is released afterwards', async () => {
+  const lock = join(mkdtempSync(join(tmpdir(), 'qmd-warm-')), 'repo.lock');
+  let runs = 0;
+  await withLock(lock, async () => {
+    runs += 1;
+    await withLock(lock, async () => { runs += 1; });
+  });
+  assert.equal(runs, 1);
+  assert.equal(existsSync(lock), false);
+});
+
+test('a stale lock older than 30 minutes is replaced', async () => {
+  const lock = join(mkdtempSync(join(tmpdir(), 'qmd-warm-')), 'repo.lock');
+  writeFileSync(lock, String(Date.now() - 31 * 60_000));
+  let runs = 0;
+  await withLock(lock, async () => { runs += 1; });
+  assert.equal(runs, 1);
+});