Seven domain-eng splits peel ~200 LOC of read endpoints out of
`api/subsonic.ts`:
- `subsonicStreamUrl.ts` — `buildStreamUrl`, `coverArtCacheKey`,
`buildCoverArtUrl`, `buildDownloadUrl` (token-signed URL builders
for the four /rest endpoints we hand to the browser).
- `subsonicStarRating.ts` — `getStarred`, `star`, `unstar`,
`setRating`, `probeEntityRatingSupport`. `setRating` still triggers
the lazy `navidromeBrowse` cache invalidation; the same-folder
lazy import path is preserved.
- `subsonicSearch.ts` — `search`, `searchSongsPaged`.
- `subsonicScrobble.ts` — `scrobbleSong`, `reportNowPlaying`,
`getNowPlaying`.
- `subsonicAlbumInfo.ts` — `getAlbumInfo2`.
- `subsonicLyrics.ts` — `getLyricsBySongId`.
- `subsonicGenres.ts` — `getGenres`, `getAlbumsByGenre`.
63 external call sites migrated to direct imports. Four `vi.mock`
targets in the store-level tests pointed at `../api/subsonic` and
were updated to the new module paths.
Pure code-move. subsonic.ts: 762 → 561 LOC (−201).