test: add unit tests for safeCompare timing-safe comparison

[Sarthak-Nayak]

Closes #827

Summary of Changes:

• Exported safeCompare from src/app/api/webhooks/github/route.ts to make it accessible for the test runner.
• Added a comprehensive Vitest unit test suite covering:
  • Immediate false returns on length mismatch (before timingSafeEqual).
  • Correct true evaluations on identical strings.
  • Safe handling of empty strings without exceptions.
• Integrated a mock/spy on crypto.timingSafeEqual to actively verify that the timing-safe comparison logic is triggered appropriately.

[vercel]

@Sarthak-Nayak is attempting to deploy a commit to the PRIYANSHU DOSHI's projects Team on Vercel.

A member of the Team first needs to authorize it.

[github-actions]

GSSoC Label Checklist 🏷️

@Priyanshu-byte-coder — please apply the appropriate labels before merging:

Difficulty (pick one):

• level:beginner — 20 pts
• level:intermediate — 35 pts
• level:advanced — 55 pts
• level:critical — 80 pts

Quality (optional):

• quality:clean — ×1.2 multiplier
• quality:exceptional — ×1.5 multiplier

Validation (required to score):

• gssoc:approved — counts for points
• gssoc:invalid / gssoc:spam / gssoc:ai-slop — does not score

Type labels (type:*) are auto-detected from files and title. Review and adjust if needed.
Points formula: (difficulty × quality_multiplier) + type_bonus

[github-actions]

Thanks for your first PR on DevTrack! 🎉

A maintainer will review it within 48 hours. While you wait:

• Make sure CI is passing (type-check + lint)
• Double-check the PR description is filled out and the issue is linked
• Feel free to ask questions in Discussions if you need help

If you find DevTrack useful, a ⭐ star on the repo is always appreciated — it helps the project grow and attract more contributors!

[Priyanshu-byte-coder]

Hi! This PR now has a merge conflict with main, likely on the shared e2e test files (e2e/dashboard-widgets.spec.js, e2e/auth-bypass.spec.js, e2e/landing.spec.js). Multiple PRs were merged recently and the e2e files updated. Please rebase onto the latest main:

git fetch origin
git rebase origin/main
# resolve any conflicts
git push --force-with-lease

Your actual feature/fix changes are valuable — we'd love to get this merged once rebased!

[Sarthak-Nayak]

Hey @Priyanshu-byte-coder, I've successfully rebased the branch onto the latest main. The code is clean and ready for review!