test(DashboardPage): verify all three StatsCards render with correct titles (JhaSourav07#774)

▶ Description

Fixes JhaSourav07#742

This PR improves test coverage for the DashboardPage by verifying that
all three "StatsCard" components render correctly with the expected
titles and values.

▶ Changes Made
Verified the following StatsCard text content:
● "Current Streak: 5"
● "Peak Streak: 15"
● "Contributions: 500"

Added a new assertion to ensure exactly three StatsCard components are
rendered:
"ts id="kgduut"
expect(screen.getAllByTestId('stats-card')).toHaveLength(3);"

▶ Pillar
Testing / Quality Assurance

▶ Validation
Successfully ran the complete Vitest test suite locally.
"txt id='uw3jzu'
Test Files 27 passed (27)
Tests 353 passed (353)"
All existing tests continue to pass successfully.


▶ Why This Matters
This improves dashboard reliability by ensuring:
● all expected statistics render consistently
● the exact number of StatsCard components is validated
● future UI regressions can be caught automatically


▶ Checklist
[x] Added StatsCard count assertion
[x] Verified all required stat titles
[x] Followed existing testing conventions
[x] All tests passing
[x] No unrelated files modified


<img width="1920" height="1080" alt="Screenshot 2026-05-27 230731"
src="https://github.com/user-attachments/assets/668e1ea7-a78c-4f35-8996-4c420b999c6a"
/>
<img width="1920" height="1080" alt="Screenshot 2026-05-27 230759"
src="https://github.com/user-attachments/assets/45424146-ec96-496e-8988-c242a496cd86"
/>

Author: JhaSourav07