fix(player): persist player prefs outside quota-bound queue blob (#958)

* fix(player): persist volume/repeat in dedicated localStorage key

Player prefs were bundled with the full queue blob in psysonic-player; after
thin-state #872 a large queue can exceed the quota and safeStorage silently
drops every write, so volume and repeat mode stopped surviving restarts.
Move them to psysonic_player_prefs, gate main-blob writes until rehydrate,
and sync volume to the Rust engine on startup.

* fix(player): split queue visibility and Last.fm cache from main persist blob

Move isQueueVisible and lastfmLovedCache to dedicated localStorage keys so
they keep saving when psysonic-player hits the quota on large queues. Include
the new keys in settings backup export.

* docs: note player prefs persist fix in CHANGELOG and credits (PR #958)

src/store/lastfmLovedCacheStorage.test.ts

@@ -0,0 +1,59 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest';
+import {
+  persistLastfmLovedCache,
+  readInitialLastfmLovedCache,
+} from './lastfmLovedCacheStorage';
+
+const CACHE_KEY = 'psysonic_lastfm_loved_cache';
+const LEGACY_KEY = 'psysonic-player';
+
+beforeEach(() => {
+  window.localStorage.clear();
+});
+
+afterEach(() => {
+  window.localStorage.clear();
+});
+
+describe('readInitialLastfmLovedCache', () => {
+  it('defaults to an empty object when nothing is stored', () => {
+    expect(readInitialLastfmLovedCache()).toEqual({});
+  });
+
+  it('reads the dedicated cache key and drops non-boolean entries', () => {
+    window.localStorage.setItem(
+      CACHE_KEY,
+      JSON.stringify({ 'Hello::Adele': true, 'Bad::': false, '': true, n: 1 }),
+    );
+    expect(readInitialLastfmLovedCache()).toEqual({ 'Hello::Adele': true, 'Bad::': false });
+  });
+
+  it('falls back to the legacy psysonic-player blob', () => {
+    window.localStorage.setItem(
+      LEGACY_KEY,
+      JSON.stringify({
+        state: {
+          lastfmLovedCache: { 'T::A': true },
+          queueItems: [],
+        },
+      }),
+    );
+    expect(readInitialLastfmLovedCache()).toEqual({ 'T::A': true });
+  });
+
+  it('prefers the dedicated key over the legacy blob', () => {
+    window.localStorage.setItem(CACHE_KEY, JSON.stringify({ 'A::B': false }));
+    window.localStorage.setItem(
+      LEGACY_KEY,
+      JSON.stringify({ state: { lastfmLovedCache: { 'A::B': true } } }),
+    );
+    expect(readInitialLastfmLovedCache()).toEqual({ 'A::B': false });
+  });
+});
+
+describe('persistLastfmLovedCache', () => {
+  it('round-trips through readInitialLastfmLovedCache', () => {
+    persistLastfmLovedCache({ 'Song::Artist': true });
+    expect(readInitialLastfmLovedCache()).toEqual({ 'Song::Artist': true });
+  });
+});