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).
peter
d49bf3bb42