Add chapter skip and 10s seek controls to audio players

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/hooks/useAudio.js

@@ -80,6 +80,22 @@ export function useAudio(readerBookAbbrev, readerChapter) {
     }
   };
 
+  const handleSeekAudio = (deltaSeconds) => {
+    if (!audioRef.current) return;
+    const el = audioRef.current;
+    const duration = Number.isFinite(el.duration) ? el.duration : Infinity;
+    el.currentTime = Math.min(Math.max(el.currentTime + deltaSeconds, 0), duration);
+  };
+
+  const handleSkipBookChapter = () => {
+    const nextChapter = audioStateRef.current.chapter + 1;
+    if (nextChapter > audioStateRef.current.total) return;
+    audioModeRef.current = 'book';
+    playAudioChapter(audioBookRef.current, nextChapter, audioNarratorRef.current).catch(() =>
+      setAudioState({ status: 'error', chapter: 0, total: 0 }),
+    );
+  };
+
   const handlePlayReaderAudio = async () => {
     audioModeRef.current = 'reader';
     try {
@@ -131,6 +147,8 @@ export function useAudio(readerBookAbbrev, readerChapter) {
     handlePlayBookAudio,
     handleStopBookAudio,
     handleToggleBookAudioPause,
+    handleSkipBookChapter,
+    handleSeekAudio,
     readerAudioState,
     handlePlayReaderAudio,
     handleToggleReaderAudioPause,