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>
Provenance "View post" deep-links to /posts?post_id=X, which now opens the
feed centered on that post with infinite load in BOTH directions.
Backend: PostFeedService.scroll gains a direction (older|newer); new
around(post_id) returns a window of newer + the post + older with a cursor
for each end. /api/posts accepts ?around= and ?direction=. + API tests.
Frontend: posts store gains loadAround/loadOlder/loadNewer (older appends,
newer prepends) with per-end cursors; PostsView's anchored mode scrolls to
the post, observes top + bottom sentinels, and preserves scroll position on
upward prepend so the page doesn't jump. Normal feed mode unchanged.
Closes the remaining half of the post-navigation work.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen