test(trip-cover): cover-strip + retina-cap regression; bump user pin

- trip-header/trips-list specs now assert the cropZoom wide-strip aspect
  and the all-or-nothing retina rule (1x-only for sub-2w sources), and a
  new regression on us-canada-mex-2024 covers the reported portrait-blur
- remove the orphaned AE4 test (no-photos-demo fixture was deleted)
- backlog: full-res pixelfed reimport (luxury quality item)
- plan: record the cover-quality follow-up + AE4 fixture removal
- bump user pin -> 536ca20 (trip-description-hero cover fix)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RDS6t8wcpbwKvvrxykVQ5K

docs/working/backlog.md

@@ -15,6 +15,12 @@ Ideas and improvements not yet planned or scheduled.
 
 ---
 
+## Content quality — luxury improvements (much later)
+
+- [ ] **Re-import pixelfed photos at full resolution** — the current import pulled pixelfed's optimised web renditions, so imported images cap at ~1440px on the long edge (portraits are 700–1200px wide). This is fine for the feed and 1x banners, but the retina cover 2x only kicks in for genuinely wide (≥1440px) sources, so auto-picked trip banners are currently 1x-only. Find the original high-quality versions in the local filesystem and re-import them (or point the pipeline at the originals rather than the pixelfed web renditions). Purely a quality upgrade — no functional gap; future content shot/stored at full res won't have this ceiling.
+
+---
+
 ## GPX Manager (`/gpx-manager`)
 
 - [ ] **Polish the UI** — the current design is functional but bare; align with the Field Notes aesthetic, add better empty states, drag-and-drop upload area