✨ v3 theme: glass UI, landing layout, a11y, perf, print styles

Floating glass header with ⌘K search, landing homepage layout with
hero image and GitHub-stars CTA, background canvas with dissolving
heroes, burufugu colour scheme, movie-quote 404, taxonomy pills,
keyboard/ARIA accessibility across menus, search and tabs, idle-
loaded third-party scripts, and dedicated print styles.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

layouts/_default/terms.html

@@ -36,7 +36,7 @@
     </section>
   {{ else }}
 
-    <section class="flex flex-wrap max-w-prose -mx-2 overflow-hidden">
+    <section class="mt-6 flex max-w-prose flex-wrap gap-2">
       {{ range .Data.Terms }}
         {{ partial "term-link/text.html" . }}
       {{ end }}