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/hooks/useLyrics.ts

@@ -0,0 +1,125 @@
+import { useEffect, useState } from 'react';
+import { fetchLyrics, parseLrc, LrcLine } from '../api/lrclib';
+import { getLyricsBySongId, SubsonicStructuredLyrics } from '../api/subsonic';
+import { useAuthStore } from '../store/authStore';
+import type { Track } from '../store/playerStore';
+
+export type LyricsSource = 'server' | 'lrclib';
+
+export interface CachedLyrics {
+  syncedLines: LrcLine[] | null;
+  plainLyrics: string | null;
+  source: LyricsSource | null;
+  notFound: boolean;
+}
+
+// Session-level cache — survives tab switches and component unmount/remount.
+export const lyricsCache = new Map<string, CachedLyrics>();
+
+/** Convert structured Subsonic lyrics (ms timestamps) into LrcLine[] or plain text. */
+export function parseStructuredLyrics(
+  lyrics: SubsonicStructuredLyrics,
+): Pick<CachedLyrics, 'syncedLines' | 'plainLyrics'> {
+  if (lyrics.issynced && lyrics.line.length > 0) {
+    const lines: LrcLine[] = lyrics.line
+      .filter(l => l.start !== undefined)
+      .map(l => ({ time: l.start! / 1000, text: l.value.trim() }))
+      .sort((a, b) => a.time - b.time);
+    if (lines.length > 0) return { syncedLines: lines, plainLyrics: null };
+  }
+  const plain = lyrics.line.map(l => l.value).join('\n').trim();
+  return { syncedLines: null, plainLyrics: plain || null };
+}
+
+export interface UseLyricsResult {
+  syncedLines: LrcLine[] | null;
+  plainLyrics: string | null;
+  source: LyricsSource | null;
+  loading: boolean;
+  notFound: boolean;
+}
+
+export function useLyrics(currentTrack: Track | null): UseLyricsResult {
+  const cached = currentTrack ? lyricsCache.get(currentTrack.id) : undefined;
+  const lyricsServerFirst = useAuthStore(s => s.lyricsServerFirst);
+
+  const [loading, setLoading]         = useState(!cached && !!currentTrack);
+  const [syncedLines, setSyncedLines] = useState<LrcLine[] | null>(cached?.syncedLines ?? null);
+  const [plainLyrics, setPlainLyrics] = useState<string | null>(cached?.plainLyrics ?? null);
+  const [source, setSource]           = useState<LyricsSource | null>(cached?.source ?? null);
+  const [notFound, setNotFound]       = useState(cached?.notFound ?? false);
+
+  useEffect(() => {
+    if (!currentTrack) return;
+
+    const hit = lyricsCache.get(currentTrack.id);
+    if (hit) {
+      setSyncedLines(hit.syncedLines);
+      setPlainLyrics(hit.plainLyrics);
+      setSource(hit.source);
+      setNotFound(hit.notFound);
+      setLoading(false);
+      return;
+    }
+
+    let cancelled = false;
+    setSyncedLines(null);
+    setPlainLyrics(null);
+    setSource(null);
+    setNotFound(false);
+    setLoading(true);
+
+    const store = (entry: CachedLyrics) => {
+      if (cancelled) return;
+      lyricsCache.set(currentTrack.id, entry);
+      setSyncedLines(entry.syncedLines);
+      setPlainLyrics(entry.plainLyrics);
+      setSource(entry.source);
+      setNotFound(entry.notFound);
+      setLoading(false);
+    };
+
+    const fetchServer = async (): Promise<boolean> => {
+      const structured = await getLyricsBySongId(currentTrack.id);
+      if (!structured) return false;
+      const parsed = parseStructuredLyrics(structured);
+      if (!parsed.syncedLines && !parsed.plainLyrics) return false;
+      store({ ...parsed, source: 'server', notFound: false });
+      return true;
+    };
+
+    const fetchLrclibFn = async (): Promise<boolean> => {
+      try {
+        const result = await fetchLyrics(
+          currentTrack.artist ?? '',
+          currentTrack.title,
+          currentTrack.album ?? '',
+          currentTrack.duration ?? 0,
+        );
+        if (!result || (!result.syncedLyrics && !result.plainLyrics)) return false;
+        const lines = result.syncedLyrics ? parseLrc(result.syncedLyrics) : null;
+        const synced = lines && lines.length > 0 ? lines : null;
+        store({ syncedLines: synced, plainLyrics: result.plainLyrics, source: 'lrclib', notFound: false });
+        return true;
+      } catch {
+        return false;
+      }
+    };
+
+    (async () => {
+      const [first, second] = lyricsServerFirst
+        ? [fetchServer, fetchLrclibFn]
+        : [fetchLrclibFn, fetchServer];
+
+      if (cancelled) return;
+      if (await first()) return;
+      if (cancelled) return;
+      if (await second()) return;
+      if (!cancelled) store({ syncedLines: null, plainLyrics: null, source: null, notFound: true });
+    })();
+
+    return () => { cancelled = true; };
+  }, [currentTrack?.id]); // eslint-disable-line react-hooks/exhaustive-deps
+
+  return { syncedLines, plainLyrics, source, loading, notFound };
+}