Sixth lift in the PR5 discovery-workers series. Pulls the 323-line
Beatport chart discovery worker out of `web_server.py` into its own
focused module under `core/discovery/`. Pure 1:1 lift — wrapper keeps
the original entry-point name.
What the Beatport discovery worker does:
1. Pause enrichment workers (release shared resources).
2. For each Beatport track:
- Cancellation gate (state['phase'] != 'discovering').
- Clean Beatport text (artist/title) of common annotations via
`clean_beatport_text` helper.
- Single-string artist normalization for "CID,Taylr Renee"-style
entries — split on comma, take the first.
- Discovery cache lookup; cache hit short-circuits the search and
normalizes cached artists from ['str'] → [{'name': 'str'}] to
match the frontend's expected list-of-objects shape.
- matching_engine search-query generation (with high min_confidence
of 0.9 to avoid bad matches).
- Strategy 1: scored candidates from initial Spotify/iTunes searches.
- Strategy 4: extended search with limit=50 if no high-confidence
match found.
- On Spotify match: format artists as [{'name': str}] objects, pull
full album object from raw cache when available, fallback to
reconstructed album dict otherwise.
- On iTunes match: format with image_url-derived album.images entry
(300x300 spec), source set to discovery_source.
- Save matched result to discovery cache when confidence >= 0.75
(note: lower than search threshold; discovery still benefits from
these less-confident matches as user-visible suggestions).
- On miss: Wing It stub stored as 'wing-it' status (success ticked).
3. After all tracks: phase='discovered', activity feed entry, sync
discovery results back to mirrored playlist via
`_sync_discovery_results_to_mirrored` with 'beatport' tag.
4. On error: state['phase']='fresh' + status='error'.
5. Finally: resume enrichment workers.
Dependencies injected via `BeatportDiscoveryDeps` (17 fields) —
beatport_chart_states, spotify_client, matching_engine, plus 14
callable helpers (pause/resume enrichment, get_active_discovery_source,
get_metadata_fallback_client, clean_beatport_text,
get_discovery_cache_key, get_database, validate_discovery_cache_artist,
spotify_rate_limited, discovery_score_candidates, get_metadata_cache,
build_discovery_wing_it_stub, add_activity_item,
sync_discovery_results_to_mirrored).
Diff vs original after `deps.X` → global X normalization is **zero
differences** — 323 lines orig = 323 lines lifted, byte-identical body
(including all whitespace, comments, log strings).
Tests: 12 new under tests/discovery/test_discovery_beatport.py covering
cache hit short-circuit (with cached-artist normalization), Spotify
match formatting (list and string artist inputs), iTunes match
(image_url to album.images), Wing It fallback, cancellation
(phase change), completion phase update, activity feed entry, mirrored
sync invocation, top-level error handler, per-track error handling,
comma-separated artist split.
Full suite: 1130 passing (was 1118). Ruff clean.
Broque Thomas