Phase 6: sync jobs, inquiry and order forms

- Sync scheduler in the content service with a per-job cache (sync_cache),
  sync_runs reporting and Healthchecks pings. Jobs: Archidekt, BoardGameGeek,
  cover art (Open Library, TMDB, AniList), Suwayomi and Kavita reading
  progress, Bambuddy filament and Homebox material stock. A note's own value
  always wins over a synced one.
- PersonalReader: updates only Library notes with a matching anilistId,
  changes to Greg's notes are held for review; Reading series with no note
  show as suggestions on the admin Overview.
- /api/inquiries and /api/orders: Turnstile, rate limits, a saved copy in the
  content service (intake token) plus email over SMTP. Orders are re-checked
  against the live notes: accepted only when the category's ordersOpen is
  true and the line has capacity.
- Admin Inbox for saved submissions. Options' inStock is optional so synced
  stock can fill it. All settings from process.env; .env.example per service.
- Sources could not be reached from the build environment; parsers are tested
  against fixtures labelled as not live.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012aSbo2D1qP8cMFQCykf7kx

services/site/src/pages/library/shelf.astro

@@ -3,7 +3,8 @@
  * The Shelf: every board game. What is on the table (from the status log),
  * then the collection, filtered by how it plays, owned, want to play and
  * favorites, and sorted by last played, A to Z or recently added. Player
- * counts and play times come from BoardGameGeek later; no filter for them yet.
+ * counts, play times and box art sync from BoardGameGeek (a cover set in the
+ * note wins); no filter for them yet.
  */
 import Divider from "@gk/ui/components/Divider.astro";
 import FilterGroup from "@gk/ui/components/FilterGroup.astro";