feat(feedback): render links in the operator reply (open in a new tab)

Linkify the operator reply on the feedback screen: http/https/ftp/mailto/tel URLs
become anchors (target=_blank rel=noopener), everything else stays escaped text.
A small whitelisted regex (no dependency) — the reply is operator-authored, so
explicit schemes suffice; dangerous schemes (javascript:/data:) are never linked,
and \b avoids matching a scheme inside a word (hotel:, email:).

ui/e2e/feedback.spec.ts

@@ -43,7 +43,11 @@ test('feedback: an operator reply raises the badge and shows on the screen', asy
 
   await openFeedback(page);
   await expect(page.getByText('Reply to your last message')).toBeVisible();
-  await expect(page.getByText(/looking into it/)).toBeVisible();
+  // A URL in the reply renders as a link that opens in a new tab.
+  const link = page.getByRole('link', { name: 'https://example.com/help' });
+  await expect(link).toBeVisible();
+  await expect(link).toHaveAttribute('target', '_blank');
+  await expect(link).toHaveAttribute('rel', /noopener/);
 });
 
 test('feedback: sending a new message clears the previous reply', async ({ page }) => {