browser-harness: Chrome runs in its own process group and close() stops that group (only what this launch started: the browser and its renderer/GPU helpers, which outlived a killed browser and kept writing), then removes the temporary profile with retries and resolves once it is gone; if the process ends first, an exit handler does the same. The profile used to be removed on an unref'd timer that never ran when the process ended right after, leaving one per run on a nearly full disk (H7). run() awaits close(); the Chrome test checks the profile is gone

ddiff --git a/browser-harness.js b/browser-harness.js
iindex c6a49f5..8e99bcf 100644
---- a/browser-harness.js
++++ b/browser-harness.js
@@@ -122,7 +122,8 @@ function connect(wsUrl, onClose) {
  
  /**
   * Starts headless Chrome (or attaches to one at chrome.browserURL, e.g. through an ssh tunnel) and answers
-- * { version, userAgent, send, newContext(), close() }. close() kills only the process it started.
++ * { version, userAgent, send, newContext(), close() }. close() kills only the process it started and resolves once
++ * its temporary profile is removed.
   */
  async function launch({ bin, browserURL, tmpDir, args = [], sandbox = false, headless = true } = {}) {
      let proc = null, profile = null, wsUrl;
@@@ -139,7 +140,7 @@ async function launch({ bin, browserURL, tmpDir, args = [], sandbox = false, hea
              '--disable-background-networking', '--disable-component-update', '--disable-sync', '--disable-default-apps',
              // No back/forward cache: kept pages would count in the navigation check's heap, node and document samples.
              '--mute-audio', '--disk-cache-size=16777216', '--window-size=1280,900', '--disable-features=BackForwardCache', ...args, 'about:blank',
--        ], { stdio: 'ignore' });
++        ], { stdio: 'ignore', detached: true }); // its own process group: close() stops Chrome and its helpers together
          const portFile = path.join(profile, 'DevToolsActivePort');
          for (let i = 0; i < 200 && !wsUrl; i++) {
              if (proc.exitCode != null) break;
@@@ -154,11 +155,26 @@ async function launch({ bin, browserURL, tmpDir, args = [], sandbox = false, hea
      const conn = connect(wsUrl);
      await conn.opened;
      const version = await conn.send('Browser.getVersion');
--    const close = () => {
++    // Only the Chrome this launch started: its process group (the browser and its renderer/GPU helpers, which
++    // otherwise outlive a killed browser for a moment and keep writing to the profile).
++    const killChrome = () => { if (!proc) return; try { process.kill(-proc.pid, 'SIGKILL'); } catch { try { proc.kill('SIGKILL'); } catch { /* gone */ } } };
++    const removeProfile = () => { if (profile) { try { fs.rmSync(profile, { recursive: true, force: true, maxRetries: 3, retryDelay: 50 }); } catch { /* retried by close() */ } } };
++    // A leftover profile per run fills a small disk: if this process ends first, Chrome and the profile go too.
++    const onExit = () => { killChrome(); removeProfile(); };
++    if (proc) process.once('exit', onExit);
++    /** Closes the connection, stops only the Chrome this launch started, and resolves once its profile is gone. */
++    const close = () => new Promise((resolve) => {
          conn.close();
--        if (proc) { proc.kill('SIGKILL'); }
--        if (profile) { const p = profile; setTimeout(() => fs.rmSync(p, { recursive: true, force: true }), 300).unref(); }
--    };
++        if (!proc) { resolve(); return; }
++        const done = async () => {
++            for (let i = 0; i < 30 && profile && fs.existsSync(profile); i++) { removeProfile(); if (fs.existsSync(profile)) await sleep(100); }
++            process.removeListener('exit', onExit);
++            resolve();
++        };
++        if (proc.exitCode != null || proc.signalCode != null) { killChrome(); done(); return; }
++        proc.once('exit', () => { killChrome(); done(); });
++        killChrome();
++    });
      return {
          version: version.product, userAgent: version.userAgent, pid: proc ? proc.pid : null,
          send: conn.send, on: conn.on, off: conn.off, get closed() { return conn.closed; }, close,
@@@ -802,7 +818,7 @@ async function run(opts = {}) {
      } catch (e) {
          report.error = e.message;
      } finally {
--        if (own) browser.close();
++        if (own) await browser.close();
      }
      report.finishedAt = new Date().toISOString();
      report.summary = summarize(report);
ddiff --git a/test/browser-harness-chrome.test.js b/test/browser-harness-chrome.test.js
iindex 1243337..9303610 100644
---- a/test/browser-harness-chrome.test.js
++++ b/test/browser-harness-chrome.test.js
@@@ -45,11 +45,15 @@ const AXE_STUB = `window.axe = { run: () => Promise.resolve({ violations: locati
      });
      await new Promise((ok) => server.listen(0, '127.0.0.1', ok));
      const base = `http://127.0.0.1:${server.address().port}`;
--    const report = await h.run({
++    const tmpDir = require('fs').mkdtempSync(require('path').join(require('os').tmpdir(), 'ov-harness-test-'));
++    const report = await h.run({ chrome: { tmpDir },
          base, routes: ['/', '/b', { path: '/missing', status: 404 }, '/private'], widths: [390, 1280], settleMs: 300, idleMs: 1000,
          navigation: { from: '/spa', to: '/spa?b', laps: 4 }, axe: { source: AXE_STUB },
      });
      server.close();
++    // Chrome is gone and so is its profile (a leftover per run fills a small disk).
++    assert.deepStrictEqual(require('fs').readdirSync(tmpDir), [], 'the Chrome profile is removed when run() returns');
++    require('fs').rmdirSync(tmpDir);
      const [good, bad, missing, priv] = report.routes;
      const text = h.format(report);