refactor(lib): move songToTrack + pure server-scope helpers to lib/media; split trackServerScope

songToTrack (the canonical Subsonic-song -> Track mapper) and the pure
server-scope helpers (activeServerProfileId, stampTrackServerId/s,
isMultiServerQueue, profileIdFromQueueRef) operate only on the lib/media model +
authStore + server-key utils -- no playback-store read. Move them to lib/media so
the ~58 app-wide consumers (cover, context menus, sharing, lucky-mix, library
browse, pages, hooks) depend on lib, not on the playback feature.

trackServerScope is split: the store-reading queue helpers (queueItemRefAt,
filterQueueRefs*, activeServerQueueTrackIds) stay in
features/playback/utils/playback/trackServerScope and build on the pure lib half.

With Track/QueueItemRef (prior commit), songToTrack and shuffleArray now in lib,
the media-domain model is fully out of features/playback. The remaining
playerStoreTypes imports are PlayerState only (the store shape). tsc 0, lint 0,
full suite 2353/2353, build OK.

src/features/orbit/components/OrbitSessionBar.tsx

@@ -1,5 +1,5 @@
 import { getSong } from '@/lib/api/subsonicLibrary';
-import { songToTrack } from '@/features/playback/utils/playback/songToTrack';
+import { songToTrack } from '@/lib/media/songToTrack';
 import { useEffect, useRef, useState } from 'react';
 import { X, RefreshCw, Shuffle, Settings2, Share2, HelpCircle, Activity } from 'lucide-react';
 import { useTranslation } from 'react-i18next';

src/features/orbit/hooks/useOrbitGuest.ts

@@ -1,5 +1,5 @@
 import { getSong } from '@/lib/api/subsonicLibrary';
-import { songToTrack } from '@/features/playback/utils/playback/songToTrack';
+import { songToTrack } from '@/lib/media/songToTrack';
 import { useEffect, useRef } from 'react';
 import { useOrbitStore } from '@/features/orbit/store/orbitStore';
 import { useAuthStore } from '@/store/authStore';

src/features/orbit/hooks/useOrbitHost.ts

@@ -1,5 +1,5 @@
 import { getSong } from '@/lib/api/subsonicLibrary';
-import { songToTrack } from '@/features/playback/utils/playback/songToTrack';
+import { songToTrack } from '@/lib/media/songToTrack';
 import { useEffect } from 'react';
 import { useOrbitStore } from '@/features/orbit/store/orbitStore';
 import { usePlayerStore } from '@/features/playback/store/playerStore';

src/features/orbit/utils/guest.ts

@@ -1,6 +1,6 @@
 import { createPlaylist, deletePlaylist, getPlaylist, getPlaylists, updatePlaylist } from '@/lib/api/subsonicPlaylists';
 import { getSong } from '@/lib/api/subsonicLibrary';
-import { songToTrack } from '@/features/playback/utils/playback/songToTrack';
+import { songToTrack } from '@/lib/media/songToTrack';
 import { useAuthStore } from '@/store/authStore';
 import { useOrbitStore } from '@/features/orbit/store/orbitStore';
 import { usePlayerStore } from '@/features/playback/store/playerStore';

src/features/orbit/utils/host.test.ts

@@ -26,7 +26,7 @@ vi.mock('@/store/authStore', () => ({ useAuthStore: { getState: () => ({}) } }))
 vi.mock('@/features/playback/store/playerStore', () => ({ usePlayerStore: { getState: () => ({ enqueue: vi.fn() }) } }));
 vi.mock('@/lib/api/subsonicPlaylists', () => ({ createPlaylist: vi.fn(), deletePlaylist: vi.fn() }));
 vi.mock('@/lib/api/subsonicLibrary', () => ({ getSong: vi.fn() }));
-vi.mock('@/features/playback/utils/playback/songToTrack', () => ({ songToTrack: vi.fn() }));
+vi.mock('@/lib/media/songToTrack', () => ({ songToTrack: vi.fn() }));
 
 import { updateOrbitSettings } from '@/features/orbit/utils/host';
 

src/features/orbit/utils/host.ts

@@ -1,6 +1,6 @@
 import { createPlaylist, deletePlaylist } from '@/lib/api/subsonicPlaylists';
 import { getSong } from '@/lib/api/subsonicLibrary';
-import { songToTrack } from '@/features/playback/utils/playback/songToTrack';
+import { songToTrack } from '@/lib/media/songToTrack';
 import { useAuthStore } from '@/store/authStore';
 import { useOrbitStore } from '@/features/orbit/store/orbitStore';
 import { usePlayerStore } from '@/features/playback/store/playerStore';