Test(FeatureCard): Verify hover class is applied to the container (JhaSourav07#804)

## Description
Adds a test asserting the heading element has the hover class.
Fixes JhaSourav07#714 

## Pillar

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

## Visual Preview
No visual preview as this PR just adds a testcase.
## 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/components/FeatureCard.test.tsx

@@ -108,6 +108,14 @@ describe('FeatureCard', () => {
       const iconWrapper = container.querySelector('.bg-white\\/5');
       expect(iconWrapper).toBeTruthy();
     });
+
+    it('applies group-hover:text-emerald-400 to the heading', () => {
+      render(<FeatureCard {...defaultProps} />);
+
+      const heading = screen.getByRole('heading', { level: 3 });
+
+      expect(heading.className).toContain('group-hover:text-emerald-400');
+    });
   });
 
   describe('multiple instances', () => {