fix(lyrics): keep classic styles as default

Existing users keep the rail/classic experience they're used to;
the new Apple Music-like style is opt-in via the FS popover and
the Sidebar Lyrics Style setting in Appearance.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/store/authStore.ts

@@ -321,8 +321,8 @@ export const useAuthStore = create<AuthState>()(
       lyricsMode: 'standard',
       lyricsStaticOnly: false,
       showFullscreenLyrics: true,
-      fsLyricsStyle: 'apple',
+      fsLyricsStyle: 'rail',
-      sidebarLyricsStyle: 'apple',
+      sidebarLyricsStyle: 'classic',
       showFsArtistPortrait: true,
       fsPortraitDim: 28,
       showChangelogOnUpdate: true,