test(ui): verify ThemeSelector error resilience

[ThePriyanuj]

Closes #6888

[github-actions]

🚨 Hey @ThePriyanuj, the CI Pipeline is failing on this PR and it has been marked as status:blocked.

Please fix the issues before this can be reviewed. Here's how:

1. Run checks locally before pushing:

npm run format:check   # Check Prettier formatting
npm run lint           # Run ESLint
npm run typecheck      # TypeScript type check
npm run test           # Run unit tests (Vitest)
npm run build          # Verify production build passes

2. Auto-fix common issues:

npm run format         # Auto-fix formatting with Prettier
npm run lint -- --fix  # Auto-fix lint errors where possible

3. Check the full failure log here:
👉 View CI Run

Once you push a fix and the CI passes, the status:blocked label will be removed automatically. 💪

[Aamod007]

The CI checks are currently failing and this PR is blocked. Please fix the failing tests/linting so we can proceed with a full review.

[github-actions]

⚠️ Hey @ThePriyanuj, this pull request has been inactive for 3 days. It will be automatically closed in 2 days if no further activity occurs.

If you are still working on this, please push your latest changes or leave a comment to keep it active.