feat(library): match own-state on artist MBID, not just name

Own-state ("in library") relied on an exact artist-NAME match, so an owned
album whose name differed from the MB canonical (punctuation/locale/feat.)
showed as not-owned even when followed. Capture the MusicBrainz artist MBID
on LibraryItem and prefer it for matching.

- New LibraryItem.artistMbid (migration add_library_artist_mbid). Populated at
  import (pipeline) + scan, both of which already hold the resolved target;
  the pipeline also now stores rgMbid (it previously didn't). COALESCE on
  conflict backfills MBIDs on re-scan without clobbering.
- /api/artists "in library, not followed" matches by artistMbid first, name
  case-insensitively as fallback (rows predating the column). Library route
  prefers the item's own artistMbid over the release join.

Last.fm/discover own-state still use name-match (they work) — a smaller
follow-up. worker 233, web 186 tests.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

worker/lyra_worker/pipeline.py

@@ -245,15 +245,17 @@ def _import(conn: psycopg.Connection, job_id: str, target: MBTarget,
     with conn.cursor() as cur:
         cur.execute(
             'INSERT INTO "LibraryItem" (id, "requestId", artist, album, path, source, '
-            'format, "qualityClass", "trackNames", "importedAt") '
-            "VALUES (gen_random_uuid()::text, %s, %s, %s, %s, %s, %s, %s, %s, now()) "
+            'format, "qualityClass", "trackNames", "rgMbid", "artistMbid", "importedAt") '
+            "VALUES (gen_random_uuid()::text, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, now()) "
             'ON CONFLICT (artist, album) DO UPDATE SET '
             '  "requestId" = EXCLUDED."requestId", path = EXCLUDED.path, source = EXCLUDED.source, '
             '  format = EXCLUDED.format, "qualityClass" = EXCLUDED."qualityClass", '
-            '  "trackNames" = EXCLUDED."trackNames", "importedAt" = now() '
+            '  "trackNames" = EXCLUDED."trackNames", "rgMbid" = COALESCE(EXCLUDED."rgMbid", "LibraryItem"."rgMbid"), '
+            '  "artistMbid" = COALESCE(EXCLUDED."artistMbid", "LibraryItem"."artistMbid"), "importedAt" = now() '
             'WHERE EXCLUDED."qualityClass" > "LibraryItem"."qualityClass"',
             (request_id, target.artist, target.album, path, winner.source,
-             winner.quality.fmt, quality_class(winner.quality), track_names),
+             winner.quality.fmt, quality_class(winner.quality), track_names,
+             target.rg_mbid or None, target.artist_mbid or None),
         )
         cur.execute(
             "UPDATE \"Request\" SET status = 'completed' WHERE id = %s", (request_id,)

worker/lyra_worker/scan.py

@@ -84,13 +84,16 @@ def _record_owned(conn, target, quality_class: int, fmt: str, path: str, watched
         track_names = list_audio_files(path)  # capture the real on-disk tracks
         cur.execute(
             'INSERT INTO "LibraryItem" (id, "requestId", artist, album, path, source, format, '
-            '"qualityClass", "trackNames", "importedAt") '
-            "VALUES (gen_random_uuid()::text, NULL, %s, %s, %s, 'scan', %s, %s, %s, now()) "
-            # refresh trackNames on re-scan (populates items imported before this column);
-            # xmax=0 ⇒ this was an INSERT (a genuinely new library item) vs an UPDATE.
-            'ON CONFLICT (artist, album) DO UPDATE SET "trackNames" = EXCLUDED."trackNames" '
+            '"qualityClass", "trackNames", "rgMbid", "artistMbid", "importedAt") '
+            "VALUES (gen_random_uuid()::text, NULL, %s, %s, %s, 'scan', %s, %s, %s, %s, %s, now()) "
+            # refresh trackNames + MBIDs on re-scan (populates items recorded before these
+            # columns); xmax=0 ⇒ this was an INSERT (a genuinely new library item) vs an UPDATE.
+            'ON CONFLICT (artist, album) DO UPDATE SET "trackNames" = EXCLUDED."trackNames", '
+            '  "rgMbid" = COALESCE(EXCLUDED."rgMbid", "LibraryItem"."rgMbid"), '
+            '  "artistMbid" = COALESCE(EXCLUDED."artistMbid", "LibraryItem"."artistMbid") '
             "RETURNING (xmax = 0) AS inserted",
-            (target.artist, target.album, path, fmt, quality_class, track_names),
+            (target.artist, target.album, path, fmt, quality_class, track_names,
+             target.rg_mbid or None, target.artist_mbid or None),
         )
         newly = cur.fetchone()[0]  # a new LibraryItem means this album wasn't recorded before
     conn.commit()

worker/tests/test_scan.py

@@ -49,9 +49,9 @@ def test_scan_records_have_monitored_and_follows_artist(conn, tmp_path):
     assert (result.imported, result.skipped) == (1, 0)
     assert _counts(conn) == {"LibraryItem": 1, "MonitoredRelease": 1, "WatchedArtist": 1}
     with conn.cursor() as cur:
-        cur.execute('SELECT source, "qualityClass" FROM "LibraryItem" WHERE artist=%s AND album=%s',
-                    ("John Mayer", "Continuum"))
-        assert cur.fetchone() == ("scan", 3)
+        cur.execute('SELECT source, "qualityClass", "artistMbid", "rgMbid" FROM "LibraryItem" '
+                    'WHERE artist=%s AND album=%s', ("John Mayer", "Continuum"))
+        assert cur.fetchone() == ("scan", 3, "a1", "rg1")  # MBIDs captured for own-state matching
         cur.execute('SELECT monitored, state, "currentQualityClass" FROM "MonitoredRelease" WHERE "rgMbid"=%s',
                     ("rg1",))
         assert cur.fetchone() == (True, "fulfilled", 3)