test(LandingPage): verify 3 FeatureCards render with correct titles (JhaSourav07#767)

## Description
Fixes JhaSourav07#712

## Pillar
- [ ] 🎨 Pillar 1 — New Theme Design
- [ ] 📐 Pillar 2 — Geometric SVG Improvement
- [ ] 🕐 Pillar 3 — Timezone Logic Optimization
- [x] 🛠️ Other (Bug fix, refactoring, docs)

## Visual Preview
N/A — test-only change, no visual output.

## Checklist before requesting a review:
- [x] I have read the `CONTRIBUTING.md` file.
- [x] I have tested these changes locally
(`localhost:3000/api/streak?user=YOUR_USERNAME`).
- [x] I have run `npm run format` and `npm run lint` locally and
resolved all errors (CI will fail otherwise).
- [x] My commits follow the Conventional Commits format (e.g.,
`feat(themes): ...`, `fix(calculate): ...`).
- [ ] I have updated `README.md` if I added a new theme or URL
parameter.
- [x] I have started the repo.
- [x] I have made sure that i have only one commit to merge in this PR.
- [ ] The SVG output matches the CommitPulse "premium quality" aesthetic
standard (no raw elements, smooth animations, correct fonts).
- [x] (Recommended) I joined the CommitPulse Discord community for
contributor discussions, mentorship, and faster PR support.

Author: JhaSourav07

app/page.test.tsx

@@ -210,11 +210,15 @@ describe('LandingPage', () => {
     expect(navigator.clipboard.writeText).not.toHaveBeenCalled();
   });
 
-  it('renders the FeatureCards', () => {
+  it('renders exactly 3 FeatureCards with correct titles', () => {
     render(<LandingPage />);
-    expect(screen.getByText('Real-time Sync')).toBeDefined();
-    expect(screen.getByText('Theme Engine')).toBeDefined();
-    expect(screen.getByText('Isometric Math')).toBeDefined();
+
+    const featureHeadings = screen.getAllByRole('heading', { level: 3 });
+
+    expect(featureHeadings).toHaveLength(3);
+
+    const titles = featureHeadings.map((h) => h.textContent);
+    expect(titles).toEqual(['Real-time Sync', 'Theme Engine', 'Isometric Math']);
   });
 
   it('renders the CustomizeCTA', () => {