A full cold sync crashed and left plex_people empty (cast/people missing in
every detail view). enrich_row_people added PlexPerson rows via the ORM with no
ON CONFLICT, and because SessionLocal is autoflush=False a person shared by two
items in the same enrich batch was queued twice -> the single batch commit
violated the unique index ix_plex_people_name and rolled the whole batch back.
Prod dodged it by building up incrementally; dev hits it on every reseed+sync.
Insert missing people via an immediately-executed pg_insert with
on_conflict_do_nothing (deduped within the cast by name, keeping the first
non-null thumb), mirroring app/sync/videos.py:_insert_stubs. The immediate
execute also lets a later row in the batch see the row via the existing-names
query and skip it; the conflict guard additionally covers the concurrent
info-page enrichment path.
Adds a DB-backed regression test: two items with overlapping cast now enrich
without a unique-violation, one row per name, and a prior-NULL headshot is
back-filled. Mutation-checked (reverting the fix reddens it).
/code-review high on S2 — 4 findings, 2 fixed, 2 no-change:
- test_plex_sync_txn: a faked PlexClient fails on the second library; asserts the
first library's row survives (per-section commit). Mutation-checked — moving the
commit back out of the loop turns it red ([] == ['1']).
- dropped the `[[quota-owns-its-session]]` memory slugs from quota.py docstrings
(a dangling private-note reference in shipped code; the reasoning is already inline).
No change: record_usage's per-call second connection is a transient spike, fine for
this app's concurrency; the two-site `with SessionLocal()` duplication isn't worth a
helper until a third caller appears.
Gate: ruff clean; DB lane 181 green.
peter