refactor(api): F.50 — extract 7 small domain modules (#615)

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).

src/store/applyQueueHistorySnapshot.ts

@@ -1,5 +1,5 @@
+import { reportNowPlaying } from '../api/subsonicScrobble';
 import { invoke } from '@tauri-apps/api/core';
-import { reportNowPlaying } from '../api/subsonic';
 import { getPlaybackSourceKind } from '../utils/resolvePlaybackUrl';
 import { useAuthStore } from './authStore';
 import {

src/store/audioEventHandlers.ts

@@ -1,7 +1,7 @@
+import { reportNowPlaying, scrobbleSong } from '../api/subsonicScrobble';
 import type { Track } from './playerStoreTypes';
 import { invoke } from '@tauri-apps/api/core';
 import { lastfmGetTrackLoved, lastfmScrobble, lastfmUpdateNowPlaying } from '../api/lastfm';
-import { reportNowPlaying, scrobbleSong } from '../api/subsonic';
 import { setDeferHotCachePrefetch } from '../utils/hotCacheGate';
 import { getPerfProbeFlags } from '../utils/perfFlags';
 import { bumpPerfCounter } from '../utils/perfTelemetry';

src/store/initAudioListeners.ts

@@ -1,9 +1,7 @@
+import { getAlbumInfo2 } from '../api/subsonicAlbumInfo';
+import { buildCoverArtUrl } from '../api/subsonicStreamUrl';
 import { invoke } from '@tauri-apps/api/core';
 import { listen } from '@tauri-apps/api/event';
-import {
-  buildCoverArtUrl,
-  getAlbumInfo2,
-} from '../api/subsonic';
 import { streamUrlTrackId } from '../utils/resolvePlaybackUrl';
 import { effectiveLoudnessPreAnalysisAttenuationDb } from '../utils/loudnessPreAnalysisSlider';
 import { normalizationAlmostEqual } from '../utils/normalizationCompare';

src/store/loudnessRefresh.test.ts

@@ -38,7 +38,7 @@ const hoisted = vi.hoisted(() => {
 });
 
 vi.mock('@tauri-apps/api/core', () => ({ invoke: hoisted.invokeMock }));
-vi.mock('../api/subsonic', () => ({ buildStreamUrl: hoisted.buildStreamUrlMock }));
+vi.mock('../api/subsonicStreamUrl', () => ({ buildStreamUrl: hoisted.buildStreamUrlMock }));
 vi.mock('../utils/redactSubsonicUrl', () => ({ redactSubsonicUrlForLog: hoisted.redactMock }));
 vi.mock('./authStore', () => ({ useAuthStore: { getState: () => hoisted.auth } }));
 vi.mock('./playerStore', () => ({

src/store/loudnessRefresh.ts

@@ -1,5 +1,5 @@
+import { buildStreamUrl } from '../api/subsonicStreamUrl';
 import { invoke } from '@tauri-apps/api/core';
-import { buildStreamUrl } from '../api/subsonic';
 import { redactSubsonicUrlForLog } from '../utils/redactSubsonicUrl';
 import { useAuthStore } from './authStore';
 import { usePlayerStore } from './playerStore';

src/store/loudnessReseed.test.ts

@@ -31,7 +31,7 @@ const hoisted = vi.hoisted(() => {
 });
 
 vi.mock('@tauri-apps/api/core', () => ({ invoke: hoisted.invokeMock }));
-vi.mock('../api/subsonic', () => ({ buildStreamUrl: hoisted.buildStreamUrlMock }));
+vi.mock('../api/subsonicStreamUrl', () => ({ buildStreamUrl: hoisted.buildStreamUrlMock }));
 vi.mock('./authStore', () => ({ useAuthStore: { getState: () => hoisted.authState } }));
 vi.mock('./playerStore', () => ({
   usePlayerStore: {

src/store/loudnessReseed.ts

@@ -1,5 +1,5 @@
+import { buildStreamUrl } from '../api/subsonicStreamUrl';
 import { invoke } from '@tauri-apps/api/core';
-import { buildStreamUrl } from '../api/subsonic';
 import { useAuthStore } from './authStore';
 import { usePlayerStore } from './playerStore';
 import { bumpWaveformRefreshGen } from './waveformRefreshGen';

src/store/offlineStore.ts

@@ -1,10 +1,10 @@
+import { buildStreamUrl } from '../api/subsonicStreamUrl';
 import { getAlbum } from '../api/subsonicLibrary';
 import { getArtist } from '../api/subsonicArtists';
 import type { SubsonicSong } from '../api/subsonicTypes';
 import { create } from 'zustand';
 import { persist, createJSONStorage } from 'zustand/middleware';
 import { invoke } from '@tauri-apps/api/core';
-import { buildStreamUrl } from '../api/subsonic';
 import { useAuthStore } from './authStore';
 import { showToast } from '../utils/toast';
 import { useOfflineJobStore, cancelledDownloads } from './offlineJobStore';

src/store/playTrackAction.ts

@@ -1,6 +1,6 @@
+import { reportNowPlaying } from '../api/subsonicScrobble';
 import { invoke } from '@tauri-apps/api/core';
 import { lastfmGetTrackLoved, lastfmUpdateNowPlaying } from '../api/lastfm';
-import { reportNowPlaying } from '../api/subsonic';
 import { setDeferHotCachePrefetch } from '../utils/hotCacheGate';
 import { orbitBulkGuard } from '../utils/orbitBulkGuard';
 import { sameQueueTrackId } from '../utils/queueIdentity';

src/store/previewStore.ts

@@ -1,7 +1,7 @@
+import { buildStreamUrl } from '../api/subsonicStreamUrl';
 import type { TrackPreviewLocation } from './authStoreTypes';
 import { create } from 'zustand';
 import { invoke } from '@tauri-apps/api/core';
-import { buildStreamUrl } from '../api/subsonic';
 import { usePlayerStore } from './playerStore';
 import { useAuthStore } from './authStore';
 import { useOrbitStore } from './orbitStore';

src/store/promoteStreamCache.test.ts

@@ -13,7 +13,7 @@ const { invokeMock, setEntryMock, buildStreamUrlMock } = vi.hoisted(() => ({
 }));
 
 vi.mock('@tauri-apps/api/core', () => ({ invoke: invokeMock }));
-vi.mock('../api/subsonic', () => ({ buildStreamUrl: buildStreamUrlMock }));
+vi.mock('../api/subsonicStreamUrl', () => ({ buildStreamUrl: buildStreamUrlMock }));
 vi.mock('./hotCacheStore', () => ({
   useHotCacheStore: { getState: () => ({ setEntry: setEntryMock }) },
 }));

src/store/promoteStreamCache.ts

@@ -1,6 +1,6 @@
+import { buildStreamUrl } from '../api/subsonicStreamUrl';
 import type { Track } from './playerStoreTypes';
 import { invoke } from '@tauri-apps/api/core';
-import { buildStreamUrl } from '../api/subsonic';
 import { useHotCacheStore } from './hotCacheStore';
 /**
  * Promote a track whose stream cache is full to the on-disk hot cache.

src/store/skipStarRating.test.ts

@@ -23,7 +23,7 @@ const { setRatingMock, recordSkipStarMock, playerSetStateMock, playerStateGet }
   };
 });
 
-vi.mock('../api/subsonic', () => ({ setRating: setRatingMock }));
+vi.mock('../api/subsonicStarRating', () => ({ setRating: setRatingMock }));
 vi.mock('./authStore', () => ({
   useAuthStore: { getState: () => ({ recordSkipStarManualAdvance: recordSkipStarMock }) },
 }));

src/store/skipStarRating.ts

@@ -1,5 +1,5 @@
+import { setRating } from '../api/subsonicStarRating';
 import type { Track } from './playerStoreTypes';
-import { setRating } from '../api/subsonic';
 import { useAuthStore } from './authStore';
 import { usePlayerStore } from './playerStore';
 /**