Best-for leaderboards, save lists, alumni permalinks

A handful of changes shipped today to help people come back and find what they were looking at last time.

• Best For leaderboards — /best-for ranks UK universities by graduate outcomes, student satisfaction, research strength, and a few more axes. Each axis links to a short explainer.
• Save a university — every university page now has a Save shortcut. Saved unis appear in your shortlist and survive across sessions.
• Alumni permalinks — every notable alumnus has a stable URL under /alumni/[slug], so you can link straight to a person.
• Faster detail pages — bumped cache TTLs to 24 hours where data only changes overnight. Page loads should feel noticeably snappier.
• Sitemap performance — switched the sitemap shard count to use Postgres’ planner row estimate instead of a full count, dropping a slow query.
• Security hardening — escaped JSON-LD payloads to close a <script> breakout vector.