Codex audit fixes: home3 read-time, /art OG/canonical, Bloom medallion centering

- home3 dropped source_read_minutes when mapping the brief item, so the badge
  only ever showed "1 min brief" — include it so "· ~N min full story" appears.
- /art is public but shipped the homepage title/canonical/OG (SSR-off shell, so
  svelte:head can't fix scrapers) — add /art to patch-static-heads.mjs.
- Bloom: center the circular motif in the tile's visual field (~43%) instead of
  the top illustration zone, so it reads as a medallion (per Jay + Codex).
- Polish: prefers-reduced-motion disables the tile hover-lift; fix stale
  patch-play-head.mjs comment reference.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/routes/home3/+page.svelte

@@ -91,7 +91,7 @@
     } catch { /* global brief */ }
     try {
       const it = (await getJSON(`/api/brief?limit=1${homeq}`))?.items?.[0];
-      if (it) news = { id: it.id, title: it.title, summary: it.summary || it.description || '', image: it.image_url || null };
+      if (it) news = { id: it.id, title: it.title, summary: it.summary || it.description || '', image: it.image_url || null, source_read_minutes: it.source_read_minutes };
       // Photos display full (cover); only wide/tall figures (diagrams) get the framed plate.
       if (news?.image) {
         const probe = new Image();