Cin pre-review followup to the standalone library parity commit. The
prior commit fixed `spotify_artist['id']` from the wrong copy-paste
value (`identification['album_id']`) to read from
`identification['artist_id']`, but the identification dict produced
by `_search_metadata_source` and `_search_single_track` never set
`artist_id` — both extracted artist NAME from the search response
and discarded the source ID sitting right next to it. Net effect of
the prior commit: artists row source-id stayed NULL, just for a more
honest reason than before.
Now properly extracted:
- `_search_metadata_source` reads `best_result.artists[0]['id']`
alongside the artist name and returns it on the identification dict
as `artist_id`.
- `_search_single_track` does the same for single-track identification.
- `_identify_single`'s tag-based-confidence path forwards
`result.get('artist_id')` so the artist source-id propagates even
when high-confidence local tags override the search result's name.
Result: identification dict now carries `artist_id` whenever the
metadata source returned an artist with an ID. The worker context
already plumbs it onto `spotify_artist['id']` and
`spotify_album['artists'][0]['id']`, so the standalone library write
finally populates `<source>_artist_id` on the artists row.
Tests added (3, in `test_auto_import_context_shape.py`):
- `test_context_artist_id_uses_identification_artist_id` — when the
identification dict carries `artist_id`, context propagates it
onto `spotify_artist['id']` AND
`spotify_album['artists'][0]['id']`. Pins that the prior copy-
paste bug (artist['id'] = album_id) doesn't return.
- `test_context_artist_id_is_empty_when_identification_missing_it` —
fallback case (filename-only identification): context gets empty
string, NOT album_id. Honest failure mode.
- `test_search_metadata_source_extracts_artist_id_from_dict_artist`
— black-box test of `_search_metadata_source`: feed it a
spotify-shaped result with `artists[0]['id']` and verify
identification dict carries it forward.
Verification:
- 11/11 context-shape tests pass (8 prior + 3 new)
- 210 imports tests pass (no regression)
- 2362 full suite passes (+3 from prior commit, +15 PR-total)
- 1 pre-existing flake (`test_watchdog_warns_about_stuck_workers`,
passes in isolation)
- Ruff clean
ec7da89434