Phase 2. Add create_playlist(title, tracks, public) to the LB client: POST /playlist/create
for the MBID, then add tracks in batches of 100 (MAX_RECORDINGS_PER_ADD) via the item/add
endpoint so 1k-track playlists don't hit a single-request cap. Returns a result dict
{success, playlist_mbid, playlist_url, added, requested, error} and never raises — partial
add failures are reported honestly (playlist created, added count accurate). Extends the
existing token-auth client; additive. 4 mocked-network tests (batching, auth, failure).
Phase 1 of exporting mirrored playlists to ListenBrainz. Two pure, fully-tested seams,
zero runtime wiring yet (additive, no regression):
- core/exports/jspf_export.py: build_jspf(title, tracks) -> ({"playlist": {...}}, summary).
LB's POST /1/playlist/create requires every track to carry a string identifier
'https://musicbrainz.org/recording/<mbid>' (text-only tracks are rejected), so tracks
without a valid recording-MBID UUID are dropped and counted in the coverage summary.
- core/exports/mbid_resolver.py: resolve_recording_mbid(artist, title, sources) — the
cheapest-first waterfall (cache -> DB -> file tag -> MusicBrainz) as a pure function over
injected (label, fn) sources. Short-circuits expensive lookups, treats a raising source
as a miss (one flaky MB call can't fail the export), reports the resolving source label.
API spec confirmed against LB docs: POST /1/playlist/create, 'Authorization: Token <t>',
{"playlist": {"title", "track": [{"identifier": "<mb recording url>", title, creator, album}]}}.
13 tests.
