add activity log with order timeline and global feed

Single activity_log table powering two views: chronological timeline
on each order detail page (replacing the old fulfilment card) and a
global feed at /admin/activity with tabs, category filters, search,
and pagination. Real-time via PubSub — new entries appear instantly,
nav badge updates across all admin pages.

Instrumented across all event points: Stripe webhooks, order notifier,
submission worker, fulfilment status worker, product sync worker, and
Oban exhausted-job telemetry. Contextual action buttons (retry
submission, retry sync, dismiss) with Oban unique constraints to
prevent double-enqueue. 90-day pruning via cron.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

PROGRESS.md

@@ -9,7 +9,7 @@
 - Image optimization pipeline (AVIF/WebP/JPEG responsive variants)
 - Shop pages (home, collections, products, cart, about, contact, error, delivery, privacy, terms)
 - Mobile-first design with bottom navigation
-- 1455 tests passing, 100% PageSpeed score
+- 1679 tests passing, 100% PageSpeed score
 - SQLite production tuning (IMMEDIATE transactions, mmap, WAL journal limit)
 - Variant selector with color swatches and size buttons
 - Session-based cart with real variant data (add/remove/quantity, cross-tab sync)
@@ -23,6 +23,7 @@
 - Transactional emails (order confirmation, shipping notification)
 - Demo content polished and ready for production
 - Privacy-first analytics with comparison mode (period deltas on stat cards)
+- Activity log with real-time global feed, order timeline, contextual retry buttons, nav badge
 
 **Tier 1 MVP complete.** CI pipeline done. Hosting & deployment done (including observability). PageSpeed CI done (99-100 mobile, 97+ desktop). Usability fixes done. Shipping costs at checkout done. Per-colour product images with gallery filtering done (both providers). Printful integration complete (sync, orders, shipping, webhooks, mockup enrichment, catalog colours). CSS migration Phases 0-7 complete — project is fully Tailwind-free (hand-written CSS, 9.8 KB gzipped shop, 17.8 KB gzipped admin). Setup and launch readiness complete — `/setup` onboarding page, dashboard launch checklist, provider registry, provider-agnostic setup status.
 
@@ -121,12 +122,12 @@ Plans: [admin-redesign.md](docs/plans/admin-redesign.md) | [admin-font-loading.m
 | ~~79~~ | ~~Auto-redirect on slug change — hook into `upsert_product/2` to detect old/new slug diff~~ | 78 | 45m | done |
 | ~~80~~ | ~~Analytics-powered 404 monitoring — query analytics on 404, FTS5 auto-resolve, broken URLs queue~~ | 78 | 2h | done |
 | ~~81~~ | ~~Admin redirects UI — active redirects, broken URLs (sorted by prior traffic), manual create~~ | 78 | 2h | done |
-| 82 | Dead link monitoring — validate stored links (internal via Phoenix.Router, external via async Oban HEAD), event-driven on product changes, admin dead links tab | page editor | 2.5h | deferred |
+| ~~82~~ | ~~Dead link monitoring — scan page blocks + nav items for broken outgoing links (internal via DB lookup, external via HTTP HEAD), daily Oban cron, event-driven on page save, admin dead links tab with re-check/ignore/source links~~ | page editor | 2.5h | done |
 | | **Activity log & order timeline** ([plan](docs/plans/activity-log.md)) | | | |
-| 89 | `activity_log` schema + migration + `ActivityLog` context (`log_event/3`, `list_for_order/1`, `list_recent/1`, `count_needing_attention/0`, `resolve/1`) | — | 1.5h | planned |
-| 90 | Instrument existing event points — stripe webhook, OrderNotifier, OrderSubmissionWorker, fulfilment status, ProductSyncWorker | 89 | 1.5h | planned |
-| 91 | Order timeline component on `/admin/orders/:id` — chronological feed replacing scattered field cards | 89 | 1.5h | planned |
-| 92 | Global `/admin/activity` LiveView — all activity + "needs attention" tab, resolve action, count badge on admin nav | 89 | 2h | planned |
+| ~~89~~ | ~~`activity_log` schema + migration + `ActivityLog` context (`log_event/3`, `list_for_order/1`, `list_recent/1`, `count_needing_attention/0`, `resolve/1`)~~ | — | 1.5h | done |
+| ~~90~~ | ~~Instrument existing event points — stripe webhook, OrderNotifier, OrderSubmissionWorker, fulfilment status, ProductSyncWorker~~ | 89 | 1.5h | done |
+| ~~91~~ | ~~Order timeline component on `/admin/orders/:id` — chronological feed replacing scattered field cards~~ | 89 | 1.5h | done |
+| ~~92~~ | ~~Global `/admin/activity` LiveView — all activity + "needs attention" tab, resolve action, count badge on admin nav + contextual retry buttons~~ | 89 | 2h | done |
 | | **Admin & page editor UX polish** ([plan](docs/plans/admin-ux-polish.md)) | | | |
 | ~~103~~ | ~~Unsaved changes warning — `beforeunload` + LiveView nav guard on page editor~~ | — | 30m | done |
 | ~~104~~ | ~~Block descriptions in picker — add subtitle text to each block type~~ | — | 45m | done |