Reader: Highlights button in the top bar

A highlighter button beside Bookmarks opens your highlights (by colour);
Bookmarks now opens the bookmarks. Each shows in the accent colour when you
have some. "H" opens the highlights.

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

src/pages/ReaderPage.jsx

@@ -102,7 +102,7 @@ export default function ReaderPage() {
   const parallelChapter = useParallelChapter(parallelId, readerBookAbbrev, readerChapter);
   const parallelSource = READER_TRANSLATIONS.find((t) => t.id === parallelId);
 
-  const [sheet, setSheet] = useState(null); // null | 'nav' | 'settings' | 'search' | 'bookmarks' | 'audio'
+  const [sheet, setSheet] = useState(null); // null | 'nav' | 'settings' | 'search' | 'bookmarks' | 'highlights' | 'audio'
   const [chromeVisible, setChromeVisible] = useState(true);
   const [readerDrawMode, setReaderDrawMode] = useState(false);
   const [selectionPicker, setSelectionPicker] = useState(null);
@@ -275,6 +275,7 @@ export default function ReaderPage() {
         else if (e.key === 'g' || e.key === 'G') { e.preventDefault(); openSheet('nav'); }
         else if (e.key === ',') { e.preventDefault(); openSheet('settings'); }
         else if (e.key === 'c' || e.key === 'C') { e.preventDefault(); openSheet('compare'); }
+        else if (e.key === 'h' || e.key === 'H') { e.preventDefault(); openSheet('highlights'); }
         else if (e.key === 'f' || e.key === 'F') setChromeVisible((v) => !v);
         else if ((e.key === 'b' || e.key === 'B') && selectedKey) {
           readerBookmarks[selectedKey] ? removeBookmark(selectedKey, readerBookmarks[selectedKey]) : toggleReaderBookmark(selectedKey);
@@ -420,7 +421,9 @@ export default function ReaderPage() {
           onOpenNavigator={() => openSheet('nav')}
           onSearch={() => openSheet('search')}
           onBookmarks={() => openSheet('bookmarks')}
-          bookmarkCount={bookmarkEntries.length + highlightEntries.length}
+          bookmarkCount={bookmarkEntries.length}
+          onHighlights={() => openSheet('highlights')}
+          highlightCount={highlightEntries.length}
           onCompare={() => openSheet('compare')} compareActive={!!parallelId}
           onSettings={() => openSheet('settings')}
           onDoneDrawing={readerDrawMode ? () => setReaderDrawMode(false) : undefined}
@@ -596,7 +599,8 @@ export default function ReaderPage() {
         onJump={jump}
       />
       <MarksSheet
-        open={sheet === 'bookmarks'} onClose={closeSheet}
+        open={sheet === 'bookmarks' || sheet === 'highlights'} onClose={closeSheet}
+        initialTab={sheet === 'bookmarks' ? 'bookmarks' : 'highlights'}
         bookmarks={bookmarkEntries} highlights={highlightEntries}
         colorLabels={readerColorLabels ?? {}} onSetLabel={setReaderColorLabel}
         onJump={jump}