Per-artist "+N" accent pill on the artists directory and a "N new since
last visit" banner inside ArtistView. Counts new IMAGES (not posts) so
multi-image posts increment correctly.
- alembic 0034: artist_visit (artist_id PK, last_viewed_at NOT NULL).
Seeds every existing artist with last_viewed_at=NOW() so the badge
starts at 0 across the board — no noisy "5000 unseen images" on
first deploy.
- ArtistService.find_or_create autoseeds a visit row alongside new
artists, so freshly imported content doesn't read as unseen.
- ArtistService.overview reads pre-visit last_viewed_at, counts images
created since, then atomically UPSERTs last_viewed_at=NOW() via
postgres ON CONFLICT DO UPDATE (no SELECT-then-INSERT race per
reference_scalar_one_or_none_duplicates). Returns the pre-update
count as `unseen_count_at_visit` so the banner has data.
- ArtistDirectoryService.list_artists adds an `unseen_count` aggregate
to each card via LEFT JOIN artist_visit + conditional COUNT. NULL
last_viewed_at (artist created before this code shipped) defensively
counts as "never visited" → all images unseen.
- Frontend: ArtistCard renders an accent pill in the preview-strip
corner when unseen_count > 0 (capped at 99+); ArtistView shows a
closable v-alert banner on initial load when
unseen_count_at_visit > 0, re-arms on slug change.
Single-row-per-artist (no user_id) — rule #47 multi-user ACL is
aspirational; widens to (user_id, artist_id) PK when User lands, per
rule #22.
Scribe plan #597.
The showcase/gallery/artist/series/post-feed APIs were constructing
thumbnail URLs from (sha256, mime). The MIME-based extension predicate
("png if image/png or image/gif else jpg") DISAGREED with the
thumbnailer's actual on-disk extension predicate ("png if alpha else
jpg"). Result: every PNG source without transparency 404'd (URL asked
.png, disk had .jpg); every WebP/AVIF source with transparency 404'd
(URL asked .jpg, disk had .png) — despite the thumbnail file existing
on disk.
The backfill task couldn't catch these because backfill checks the
ACTUAL thumbnail_path stored on the record (correct), not the URL the
browser fetches (broken derivation). So records with valid on-disk
thumbnails kept showing as broken in the UI no matter how many times
backfill ran.
Operator-flagged 2026-05-30: "the generate thumbnails function appears
to not catch all of the failed thumbnail cases" — turned out to not be
a backfill bug at all.
Fix: thumbnail_url now takes (thumbnail_path, sha256, mime) and returns
the stored path verbatim — Quart serves /images/* 1:1 from the volume
(frontend.py:20-36), so the URL IS the disk path. Falls back to the old
sha256+mime derivation only when thumbnail_path is NULL (thumbnailer
hasn't run yet); that URL will 404 in the browser until backfill catches
it, same as before the path was tracked.
All 8 callers updated: showcase_service, gallery_service (2 sites),
artist_service, series_service, post_feed_service, tag_directory_service,
artist_directory_service. The four sites whose query was raw-tuple now
also SELECT ImageRecord.thumbnail_path.
Net effect: every record that has a valid on-disk thumbnail will now
render correctly, regardless of which extension the thumbnailer chose,
without any DB migration or backfill rerun needed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>