First step of decoupling artist identity/storage/display. migration 0077 drops
uq_artist_name so the display name is free text (two genuinely different creators
can share a name); the slug stays the immutable, unique storage/identity key (the
on-disk path component — untouched, so nothing moves). ArtistService.rename +
PATCH /api/artists/<id> change the name ONLY. Frontend: inline pencil-edit on the
artist header (mirrors TagCard), slug/route unaffected so no navigation. Fixes the
operator's 'no surface to rename an artist' + the name-collision fragility.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CDgx8bQS5YrGRK76v8HUnM
encode_cursor/decode_cursor (base64 <iso8601>|<id>) were defined identically in
gallery_service AND post_feed_service, with artist_service importing gallery's
copy. Two implementations of one cursor format silently break pagination in
whichever feed drifts. Extract to services/pagination.py; gallery/post_feed/
artist all import it. Dropped now-unused base64/datetime imports.
§8b: encode_cursor/decode_cursor now defined only in pagination.py. Existing
cursor round-trip tests still cover it via the re-export. Catalog updated.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The find-or-create dance — SELECT, then a SAVEPOINT INSERT that recovers (not a
full rollback) on IntegrityError when a concurrent worker inserted first — was
hand-rolled identically in 4 async sites: ArtistService.find_or_create,
TagService.find_or_create, ExtensionService._find_or_create_artist and
._find_or_create_source. Divergent copies of exactly this pattern are how the
duplicate-row/race bugs in reference_scalar_one_or_none_duplicates crept in, so
it now lives once in services/db_helpers.get_or_create (returns (row, created);
factory adds+flushes+returns the row; caller owns the outer commit).
Over-DRY guard: SourceService's IntegrityError sites RAISE DuplicateSourceError
(reject-on-conflict, a different concept) — left alone. Importer._get_or_create
is the lone SYNC consumer (already shared by 2 callers) — stays separate, can't
cross the sync/async boundary. §8b: no hand-rolled async find-or-create remains.
Test: get_or_create creates then returns existing without re-invoking the factory.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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.
Audit 2026-06-02 flagged three SELECT-then-INSERT sites that lost the
race under concurrent writers / recovery-sweep replays, poisoning the
outer transaction with an unrecoverable IntegrityError and crashing
the calling task. Same shape as the banked 2026-05-26 ImageProvenance
incident (see reference_scalar_one_or_none_duplicates memory).
Mirrors the importer._get_or_create pattern in all three: savepoint
via begin_nested + IntegrityError rollback to that savepoint + re-
SELECT to grab the row the other worker committed first.
- importer._capture_attachment: PostAttachment.sha256 UNIQUE. attachments.store
is sha-addressed so both workers race to write the same on-disk path
(shutil.copy2 + rename is idempotent), so no extra cleanup needed.
- TagService.find_or_create: partial uniqueness index on
(name, kind, COALESCE(fandom_id, -1)). The previous docstring
claimed "INSERT ... ON CONFLICT" but the implementation was
SELECT-then-INSERT with no recovery.
- ArtistService.find_or_create: already had IntegrityError handling
but did session.rollback() (unwinds the WHOLE transaction); now
uses begin_nested + sp.rollback() so the surrounding request's
progress isn't lost.
Operator-asked 2026-06-01 after the Dymkens orphan investigation
(Scribe plan #540). The pre-2030 sidecar-synthetic Source pattern
(`sidecar:<platform>:<slug>` enabled=false rows) existed solely to
satisfy `Post.source_id NOT NULL`, and leaked into the Subscriptions
UI as phantom subscriptions. Now the data model says what's true:
filesystem-imported content with no live subscription has NULL
source_id, full stop.
## Schema (alembic 0030)
- `post.artist_id` — NEW NOT NULL FK to artist (CASCADE). Backfilled
from source.artist_id in the migration. Indexed for the artist-filter
queries.
- `post.source_id` — NOT NULL → nullable; FK ondelete CASCADE → SET
NULL. Deleting a Source detaches its Posts instead of destroying
archived content (subscription ends, archive stays).
- `image_provenance.source_id` — same nullable + SET NULL.
- Partial unique index `uq_post_artist_external_id_null_source` on
(artist_id, external_post_id) WHERE source_id IS NULL — guards
filesystem-import dedup since the existing source-bound unique
ignores NULLs (Postgres treats NULL != NULL).
- Sidecar synthetic Sources deleted: NULL out FKs in post,
image_provenance first, then DELETE FROM source WHERE url LIKE
'sidecar:%'. The Dymkens cleanup.
## Model + service changes
- `Post.source_id` → `Mapped[int | None]`; new `Post.artist_id`
denormalized.
- `ImageProvenance.source_id` → `Mapped[int | None]`.
- Importer: `_source_for_sidecar` (synthetic-creating) →
`_lookup_source_for_sidecar` (returns None when no subscription).
`_find_or_create_post` takes required `artist_id`; matches on
(source_id, external_post_id) for source-bound posts or
(artist_id, external_post_id) for NULL-source posts.
- Service queries switched off the Source detour to use Post.artist_id
directly: post_feed_service.scroll/around/get_post (LEFT JOIN to
Source so NULL-source posts surface); artist_service date_row/
activity/post_count; provenance_service.for_image/for_post (LEFT
JOIN); gallery_service._provenance_exists_where_artist via
Post.artist_id instead of ImageProvenance.source_id → Source.
- `_to_dict` and provenance dict-builders emit `"source": null` for
NULL-source rows.
## Frontend
- `ProvenancePanel.vue` + `PostCard.vue`: render `e.source?.platform
?? 'filesystem import'` so NULL-source posts get a clear
"filesystem import" affordance instead of a NaN crash.
## Tests
- `test_importer_upsert_helpers`: removed the four synthetic-anchor
tests; added `_find_or_create_post_idempotent_with_null_source`
(dedup via the partial unique index) and
`_lookup_source_for_sidecar_returns_*` (existing-subscription +
none cases). The existing `_find_or_create_post_idempotent` now
also passes `artist_id` and asserts it.
- 8 other test files updated: every direct `Post(...)` construction
gains `artist_id=<artist>.id`. The `_seed_post` helper in
`test_post_feed_service` looks up artist_id from the source row so
callsites stay one-arg.
## Verification on deploy
After alembic 0030 runs:
- `SELECT COUNT(*) FROM source WHERE url LIKE 'sidecar:%'` → 0.
- `SELECT COUNT(*) FROM post WHERE source_id IS NULL` → count of
filesystem-imported posts (Dymkens + any other historical).
- Every `post.artist_id` non-null; consistent with source.artist_id
for source-bound rows.
- Subscriptions tab: no Dymkens phantom row.
- Artist detail → Posts/Gallery: Dymkens's content still reachable
via Post.artist_id.
- Provenance panel renders "filesystem import" chip for NULL-source
posts; PostCard same.
## Out of scope
- UI to manage/delete orphan NULL-source Posts. Data model is right;
UI follows if operator wants it.
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>
bvandeusen