OWASP Nest

Added Playwright e2e smoke tests for the public mentorship programs listing page, mocking the Algolia search endpoint so the suite runs without auth flows.

Made the /gsoc year guidance fully dynamic: replaced a hardcoded year cutoff with a derived value and consolidated duplicated year logic into a single source of truth.

Removed an unused react-router-dom dependency from the frontend (the app uses next/navigation), cleaning up a stale test mock and the lockfile.