fix(scripts): smoke.mjs kills Chrome's whole process group so the temp profile is removed

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

scripts/smoke.mjs

@@ -23,8 +23,12 @@ const port = await freePort()
 const chrome = spawn(chromePath, [
   '--headless=new', `--remote-debugging-port=${port}`, `--user-data-dir=${dir}`,
   '--no-sandbox', '--disable-gpu', '--no-first-run', 'about:blank',
-], { stdio: 'ignore' })
-const cleanup = () => { chrome.kill('SIGKILL'); rmSync(dir, { recursive: true, force: true }) }
+], { stdio: 'ignore', detached: true })
+// Chrome forks helper processes; kill the whole process group, then remove the profile dir.
+const cleanup = () => {
+  try { process.kill(-chrome.pid, 'SIGKILL') } catch {}
+  rmSync(dir, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 })
+}
 const finish = (code, msg) => { if (msg) console.log(msg); cleanup(); process.exit(code) }
 process.on('SIGINT', () => finish(1, 'interrupted'))
 const timer = setTimeout(() => finish(1, 'FAIL: timed out'), 30000)