OWASP Nest

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.

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

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