SEO polish: hreflang, speakable schema, GSC-driven titles

  • en-GB locale and hreflang — UK-targeted locale tags across every page.
  • GSC-driven titles — detail-page meta titles are now rewritten using the actual queries pulling traffic from Google Search Console.
  • Speakable schema — added on subject and university pages so voice assistants can read the right summary.
  • Persistent cache — moved hot lookups behind a persistent layer; slug index added to speed up resolution.
  • Bot-aware Sentry — crawler traffic no longer pollutes the error feed.