Preferences in Settings and a home page the user chooses

Settings gets a Preferences section: theme, default Bible, the Bible new reading
plans start in, verse layout, commentary, text size, reading width, audio
narrator (the last three stay per device; text size and narrator are now
remembered). A Home page setting (My Studies, Bible Reader or Reading Plans)
decides where the app opens and where every Home button goes; already being
there means My Studies. Back arrows are labelled Home. Tests cover every page
leading back.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/hooks/useAudio.js

@@ -5,7 +5,16 @@ import { bookOptions, CHAPTER_COUNTS } from '../utils/bibleUtils.jsx';
 
 export function useAudio(readerBookAbbrev, readerChapter, readerTranslation = 'BSB') {
   const [audioBook, setAudioBook] = useState(bookOptions[0].abbrev);
-  const [audioNarrator, setAudioNarrator] = useState('souer');
+  const [audioNarrator, setAudioNarratorState] = useState(() => {
+    try {
+      const saved = localStorage.getItem('audio-narrator');
+      return ['david', 'hays', 'souer'].includes(saved) ? saved : 'souer';
+    } catch { return 'souer'; }
+  });
+  const setAudioNarrator = (id) => {
+    setAudioNarratorState(id);
+    try { localStorage.setItem('audio-narrator', id); } catch { /* storage unavailable */ }
+  };
   const [audioState, setAudioState] = useState({ status: 'idle', chapter: 0, total: 0 });
   const [readerAudioState, setReaderAudioState] = useState({ status: 'idle', chapter: 0 });
   const [audioProgress, setAudioProgress] = useState({ currentTime: 0, duration: 0 });