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/pages/ReaderPage.test.jsx

@@ -12,7 +12,7 @@ const ctx = {
   readerVerses: [{ number: 1, text: 'Now there was a man of the Pharisees.' }, { number: 2, text: 'This man came to Jesus by night.' }],
   readerTotalChapters: 21, readerLoading: false, readerError: '',
   readerInterlinear: null, readerSelectedVerse: null, setReaderSelectedVerse: vi.fn(),
-  readerFontSize: 1, setReaderFontSize: noop, readerBookmarks: {},
+  readerFontSize: 1, setReaderFontSize: noop, readerWide: false, setReaderWide: noop, readerBookmarks: {},
   readerCrossRefs: null, setReaderCrossRefs: noop, readerCrossRefsLoading: false,
   readerShowCrossRefs: false, setReaderShowCrossRefs: noop,
   readerSearch: '', setReaderSearch: noop, setReaderSearchActive: noop,