feat: v1.34.1 — fullscreen lyrics overlay, FsArt crossfade, lyrics toggle, contributor updates

- FullscreenPlayer: synced lyrics overlay (5-line rail, mask fade, click-to-seek)
- FullscreenPlayer: FsArt crossfade component with onLoad pattern, 300px art, next-track pre-fetch
- FullscreenPlayer: MicVocal lyrics toggle button next to heart (persisted in authStore)
- FullscreenPlayer: idle system — only close button auto-hides, cluster+seekbar always visible
- LyricsPane: refactored to use shared useLyrics hook (no double-fetch with FS overlay)
- authStore: showFullscreenLyrics field (default true)
- i18n: fsLyricsToggle key added to all 7 locales; ru2.ts removed (merged into ru.ts)
- Settings: Contributors updated (nisrael, cucadmuh, kilyabin); logout moved to Server tab as btn-danger
- theme.css: btn-danger style added

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/i18n.ts

@@ -6,7 +6,6 @@ import { frTranslation } from './locales/fr';
 import { nbTranslation } from './locales/nb';
 import { nlTranslation } from './locales/nl';
 import { ruTranslation } from './locales/ru';
-import { ru2Translation } from './locales/ru2';
 import { zhTranslation } from './locales/zh';
 
 const savedLanguage = localStorage.getItem('psysonic_language') || 'en';
@@ -22,7 +21,6 @@ i18n
       zh: { translation: zhTranslation },
       nb: { translation: nbTranslation },
       ru: { translation: ruTranslation },
-      ru2: { translation: ru2Translation },
     },
     lng: savedLanguage,
     fallbackLng: 'en',