feat(fullscreen): performance fixes + appearance settings

Adds no_compositing_mode Tauri command; frontend adds html.no-compositing on Linux to replace GPU-only CSS effects (backdrop-filter, filter, mask-image) with software-friendly equivalents.

Settings → Appearance → Fullscreen Player: toggle for artist portrait visibility + 0–80% dimming slider.

Fix: long words in lyric lines now wrap correctly.

src/locales/en.ts

@@ -616,6 +616,10 @@ export const enTranslation = {
     infiniteQueue: 'Infinite Queue',
     infiniteQueueDesc: 'Automatically append random tracks when the queue runs out',
     experimental: 'Experimental',
+    fsPlayerSection: 'Fullscreen Player',
+    fsShowArtistPortrait: 'Show artist photo',
+    fsShowArtistPortraitDesc: 'Display the artist photo (or album art) on the right side of the fullscreen player.',
+    fsPortraitDim: 'Photo dimming',
     seekbarStyle: 'Seekbar Style',
     seekbarStyleDesc: 'Choose the look of the player seek bar',
     seekbarWaveform: 'Waveform',