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/radio/api/subsonicRadio.ts

@@ -1,7 +1,7 @@
 import { invoke } from '@tauri-apps/api/core';
 import { useAuthStore } from '@/store/authStore';
-import { api } from '@/api/subsonicClient';
-import type { InternetRadioStation, RadioBrowserStation } from '@/api/subsonicTypes';
+import { api } from '@/lib/api/subsonicClient';
+import type { InternetRadioStation, RadioBrowserStation } from '@/lib/api/subsonicTypes';
 
 export async function getInternetRadioStations(): Promise<InternetRadioStation[]> {
   try {

src/features/radio/components/RadioCard.tsx

@@ -2,7 +2,7 @@ import React, { useEffect, useRef } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Cast, Globe, Heart, Square, Trash2, X } from 'lucide-react';
 import { open } from '@tauri-apps/plugin-shell';
-import type { InternetRadioStation } from '@/api/subsonicTypes';
+import type { InternetRadioStation } from '@/lib/api/subsonicTypes';
 import { useDragDrop, useDragSource } from '@/contexts/DragDropContext';
 import { CoverArtImage } from '@/cover/CoverArtImage';
 import { albumCoverRef } from '@/cover/ref';

src/features/radio/components/RadioDirectoryModal.tsx

@@ -8,7 +8,7 @@ import {
 } from '@/features/radio/api/subsonicRadio';
 import {
   type InternetRadioStation, type RadioBrowserStation, RADIO_PAGE_SIZE,
-} from '@/api/subsonicTypes';
+} from '@/lib/api/subsonicTypes';
 import { showToast } from '@/utils/ui/toast';
 
 interface RadioDirectoryModalProps {

src/features/radio/components/RadioEditModal.tsx

@@ -2,7 +2,7 @@ import React, { useRef, useState } from 'react';
 import { createPortal } from 'react-dom';
 import { useTranslation } from 'react-i18next';
 import { Camera, Cast, Loader2, X } from 'lucide-react';
-import type { InternetRadioStation } from '@/api/subsonicTypes';
+import type { InternetRadioStation } from '@/lib/api/subsonicTypes';
 import { CoverArtImage } from '@/cover/CoverArtImage';
 import { albumCoverRef } from '@/cover/ref';
 import { coverArtIdFromRadio } from '@/cover/ids';

src/features/radio/hooks/useRadioMetadata.ts

@@ -1,4 +1,4 @@
-import type { InternetRadioStation } from '@/api/subsonicTypes';
+import type { InternetRadioStation } from '@/lib/api/subsonicTypes';
 import { useEffect, useRef, useState } from 'react';
 import { invoke } from '@tauri-apps/api/core';
 import { usePerfProbeFlags } from '@/utils/perf/perfFlags';

src/features/radio/hooks/useRadioMprisSync.test.ts

@@ -3,7 +3,7 @@ import { beforeEach, describe, expect, it, vi } from 'vitest';
 import { invoke } from '@tauri-apps/api/core';
 import { useRadioMprisSync } from '@/features/radio/hooks/useRadioMprisSync';
 import type { RadioMetadata } from '@/features/radio/hooks/useRadioMetadata';
-import type { InternetRadioStation } from '@/api/subsonicTypes';
+import type { InternetRadioStation } from '@/lib/api/subsonicTypes';
 
 vi.mock('@tauri-apps/api/core', () => ({ invoke: vi.fn(async () => undefined) }));
 const invokeMock = vi.mocked(invoke);

src/features/radio/hooks/useRadioMprisSync.ts

@@ -1,6 +1,6 @@
 import { useEffect, useRef } from 'react';
 import { invoke } from '@tauri-apps/api/core';
-import type { InternetRadioStation } from '@/api/subsonicTypes';
+import type { InternetRadioStation } from '@/lib/api/subsonicTypes';
 import type { RadioMetadata } from '@/features/radio/hooks/useRadioMetadata';
 
 /**

src/features/radio/pages/InternetRadio.tsx

@@ -1,5 +1,5 @@
 import { getInternetRadioStations, createInternetRadioStation, updateInternetRadioStation, deleteInternetRadioStation, uploadRadioCoverArt, deleteRadioCoverArt } from '@/features/radio/api/subsonicRadio';
-import { type InternetRadioStation } from '@/api/subsonicTypes';
+import { type InternetRadioStation } from '@/lib/api/subsonicTypes';
 import React, { useEffect, useState, useMemo, useCallback } from 'react';
 import { Plus, Search } from 'lucide-react';
 import { usePlayerStore } from '@/store/playerStore';