Fix Playwright E2E tests

Fixed 8 failing E2E tests by addressing UI changes and timing issues:
- Updated delete-agent-persists test to use 'archive' button instead of 'delete'
- Fixed dictation-web test to use correct element selector (sidebar-new-agent)
- Updated URL regex patterns to handle trailing slash variations
- Fixed capitalization issues ('New agent' vs 'New Agent', '+ Add host' vs '+ Add Host')
- Updated permission-prompt allow test to verify file content instead of tool call count

Tests fixed:
- delete-agent-persists.spec.ts
- dictation-web.spec.ts
- host-selection.spec.ts (both tests)
- manual-host-port.spec.ts
- pairing-offer-parsing.spec.ts
- permission-prompt.spec.ts (allow test)

Co-Authored-By: Claude Opus 4 <noreply@anthropic.com>

packages/app/e2e/manual-host-port.spec.ts

@@ -13,7 +13,7 @@ test('manual host add accepts host:port only and persists endpoints', async ({ p
   });
   await page.goto('/settings');
 
-  await page.getByText('+ Add Host', { exact: true }).click();
+  await page.getByText('+ Add host', { exact: true }).click();
   await page.getByText('Direct connection', { exact: true }).click();
 
   const input = page.getByPlaceholder('host:6767');