Rebuild and expand E2E tests for Settings flows

- Updated Playwright config to enable 8 workers locally while maintaining single worker on CI.
- Rebuilt Settings Navigation E2E tests to verify page transitions and default redirects.
- Reintroduced Password Change E2E tests to validate form display and interactions.
- Expanded Profile Settings E2E tests to include email read-only verification.
- Marked Sessions Management E2E tests as skipped, pending route implementation confirmation.

frontend/e2e/settings-navigation.spec.ts

@@ -1,19 +1,82 @@
 /**
  * E2E Tests for Settings Navigation
- *
- * PLACEHOLDER: Settings tests require authenticated state.
- * Future implementation options:
- * 1. Add full login mock chain to setupAuthenticatedMocks()
- * 2. Use real backend in E2E (recommended for settings tests)
- * 3. Add test-only auth endpoint
- *
- * Current baseline: 47 passing E2E tests covering all auth flows
+ * Tests navigation between settings pages
  */
 
-import { test } from '@playwright/test';
+import { test, expect } from '@playwright/test';
+import { setupAuthenticatedMocks, loginViaUI } from './helpers/auth';
 
 test.describe('Settings Navigation', () => {
-  test.skip('Placeholder - requires authenticated state setup', async () => {
-    // Skipped during nuclear refactor - auth flow tests cover critical paths
+  test.beforeEach(async ({ page }) => {
+    // Set up API mocks
+    await setupAuthenticatedMocks(page);
+
+    // Login via UI to establish authenticated session
+    await loginViaUI(page);
+  });
+
+  test('should navigate from home to settings profile', async ({ page }) => {
+    // From home page
+    await expect(page).toHaveURL('/');
+
+    // Navigate to settings/profile
+    await page.goto('/settings/profile');
+
+    // Verify navigation successful
+    await expect(page).toHaveURL('/settings/profile');
+
+    // Verify page loaded
+    await expect(page.locator('h2')).toContainText('Profile');
+  });
+
+  test('should navigate from home to settings password', async ({ page }) => {
+    // From home page
+    await expect(page).toHaveURL('/');
+
+    // Navigate to settings/password
+    await page.goto('/settings/password');
+
+    // Verify navigation successful
+    await expect(page).toHaveURL('/settings/password');
+
+    // Verify page loaded
+    await expect(page.locator('h2')).toContainText('Password');
+  });
+
+  test('should navigate between settings pages', async ({ page }) => {
+    // Start at profile page
+    await page.goto('/settings/profile');
+    await expect(page.locator('h2')).toContainText('Profile');
+
+    // Navigate to password page
+    await page.goto('/settings/password');
+    await expect(page.locator('h2')).toContainText('Password');
+
+    // Navigate back to profile page
+    await page.goto('/settings/profile');
+    await expect(page.locator('h2')).toContainText('Profile');
+  });
+
+  test('should redirect from /settings to /settings/profile', async ({ page }) => {
+    // Navigate to base settings page
+    await page.goto('/settings');
+
+    // Should redirect to profile page
+    await expect(page).toHaveURL('/settings/profile');
+
+    // Verify profile page loaded
+    await expect(page.locator('h2')).toContainText('Profile');
+  });
+
+  test('should display preferences page placeholder', async ({ page }) => {
+    // Navigate to preferences page
+    await page.goto('/settings/preferences');
+
+    // Verify navigation successful
+    await expect(page).toHaveURL('/settings/preferences');
+
+    // Verify page loaded with placeholder content
+    await expect(page.locator('h2')).toContainText('Preferences');
+    await expect(page.getByText(/coming in task/i)).toBeVisible();
   });
 });