refactor(api): co-locate server-protocol clients into lib/api

Move the Subsonic + Navidrome protocol clients and the library IPC facade
(subsonic*, navidrome*, library.ts + tests) from src/api/ into src/lib/api/,
the feature-free infra layer (plan M4, decision §10.3: shared client core → lib/).
Pure move: deep-path import specifiers @/api/* -> @/lib/api/* across ~150
consumers; no behaviour change. Domain REST (lyrics/events) and cover/analysis
infra stay in src/api/ pending their own M4 placement.

tsc 0, lint 0/0, full suite 319 files / 2353 tests green.

src/features/search/components/LiveSearch.tsx

@@ -1,5 +1,5 @@
-import { subscribeLibrarySyncIdle, subscribeLibrarySyncProgress } from '@/api/library';
-import type { SearchResults, SubsonicArtist } from '@/api/subsonicTypes';
+import { subscribeLibrarySyncIdle, subscribeLibrarySyncProgress } from '@/lib/api/library';
+import type { SearchResults, SubsonicArtist } from '@/lib/api/subsonicTypes';
 import { songToTrack } from '@/utils/playback/songToTrack';
 import {
   LIVE_SEARCH_DEBOUNCE_NETWORK_MS,
@@ -30,7 +30,7 @@ import { useLibraryIndexStore } from '@/store/libraryIndexStore';
 import { useTranslation } from 'react-i18next';
 import { albumArtistDisplayName } from '@/features/album';
 import { FETCH_QUEUE_BIAS_SEARCH_ARTIST_OVER_ALBUM } from '@/ui/CachedImage';
-import type { SubsonicSong } from '@/api/subsonicTypes';
+import type { SubsonicSong } from '@/lib/api/subsonicTypes';
 import { AlbumCoverArtImage } from '@/cover/AlbumCoverArtImage';
 import { ArtistCoverArtImage } from '@/cover/ArtistCoverArtImage';
 import { CoverArtImage } from '@/cover/CoverArtImage';

src/features/search/components/MobileSearchOverlay.test.tsx

@@ -10,7 +10,7 @@ import { useLiveSearchScopeStore } from '@/store/liveSearchScopeStore';
 // function mis-flagged as a hook). Smoke-test that the recent-search path still
 // applies the term to the live-search store. Heavy collaborators are stubbed.
 vi.mock('@/features/search/hooks/useShareSearch', () => ({ useShareSearch: () => ({ shareMatch: null }) }));
-vi.mock('@/api/subsonicSearch', () => ({
+vi.mock('@/lib/api/subsonicSearch', () => ({
   search: vi.fn(() => Promise.resolve({ artists: [], albums: [], songs: [] })),
 }));
 vi.mock('@/cover/AlbumCoverArtImage', () => ({ AlbumCoverArtImage: () => null }));

src/features/search/components/MobileSearchOverlay.tsx

@@ -1,5 +1,5 @@
-import { search } from '@/api/subsonicSearch';
-import type { SearchResults, SubsonicArtist } from '@/api/subsonicTypes';
+import { search } from '@/lib/api/subsonicSearch';
+import type { SearchResults, SubsonicArtist } from '@/lib/api/subsonicTypes';
 import { songToTrack } from '@/utils/playback/songToTrack';
 import { useLiveSearchScopeStore } from '@/store/liveSearchScopeStore';
 import React, { useState, useEffect, useRef, useCallback, useMemo } from 'react';

src/features/search/components/ShareQueuePreviewModal.tsx

@@ -2,7 +2,7 @@ import React, { useEffect } from 'react';
 import { createPortal } from 'react-dom';
 import { Music, X } from 'lucide-react';
 import { useTranslation } from 'react-i18next';
-import type { SubsonicSong } from '@/api/subsonicTypes';
+import type { SubsonicSong } from '@/lib/api/subsonicTypes';
 import type { ServerProfile } from '@/store/authStoreTypes';
 import { formatTrackTime } from '@/utils/format/formatDuration';
 import type { ShareQueuePreviewState } from '@/features/search/hooks/useShareQueuePreview';

src/features/search/components/ShareSearchResults.tsx

@@ -2,7 +2,7 @@ import React, { useEffect, useState } from 'react';
 import { Disc3, Eye, Link2, ListPlus, Music, Users } from 'lucide-react';
 import { useTranslation } from 'react-i18next';
 import type { TFunction } from 'i18next';
-import type { SubsonicArtist } from '@/api/subsonicTypes';
+import type { SubsonicArtist } from '@/lib/api/subsonicTypes';
 import type { ServerProfile } from '@/store/authStoreTypes';
 import { songToTrack } from '@/utils/playback/songToTrack';
 import { activateShareSearchServer } from '@/utils/share/enqueueShareSearchPayload';

src/features/search/hooks/useShareQueuePreview.ts

@@ -1,5 +1,5 @@
 import { useEffect, useState } from 'react';
-import type { SubsonicSong } from '@/api/subsonicTypes';
+import type { SubsonicSong } from '@/lib/api/subsonicTypes';
 import {
   resolveShareSearchPayload,
   type ShareSearchResolveResult,

src/features/search/hooks/useShareSearchPreview.ts

@@ -1,5 +1,5 @@
 import { useEffect, useState } from 'react';
-import type { SubsonicAlbum, SubsonicArtist, SubsonicSong } from '@/api/subsonicTypes';
+import type { SubsonicAlbum, SubsonicArtist, SubsonicSong } from '@/lib/api/subsonicTypes';
 import {
   resolveShareSearchAlbum,
   resolveShareSearchArtist,

src/features/search/pages/SearchBrowsePage.tsx

@@ -1,7 +1,7 @@
-import { getGenres, getAlbumsByGenre } from '@/api/subsonicGenres';
-import { search, searchSongsPaged } from '@/api/subsonicSearch';
-import { getRandomSongs } from '@/api/subsonicLibrary';
-import type { SubsonicGenre, SubsonicArtist, SubsonicAlbum, SubsonicSong } from '@/api/subsonicTypes';
+import { getGenres, getAlbumsByGenre } from '@/lib/api/subsonicGenres';
+import { search, searchSongsPaged } from '@/lib/api/subsonicSearch';
+import { getRandomSongs } from '@/lib/api/subsonicLibrary';
+import type { SubsonicGenre, SubsonicArtist, SubsonicAlbum, SubsonicSong } from '@/lib/api/subsonicTypes';
 import React, { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState } from 'react';
 import { useLocation, useNavigate, useNavigationType, useSearchParams } from 'react-router-dom';
 import { SlidersVertical, Search, X } from 'lucide-react';