fix: chapter list toggle no longer overwrites title span with arrow

scraper/internal/server/ui.go

@@ -2311,7 +2311,6 @@ const chapterTmpl = `
   // ── panel toggles (chapter list / settings) ───────────────────────────────────
   window.closeChapterList = function () {
     chapterListPanel.style.display = 'none';
-    chapterListBtn.querySelector('span:last-child').innerHTML = '▼';
   };
   window.toggleChapterList = function () {
     var open = chapterListPanel.style.display !== 'none';
@@ -2320,7 +2319,6 @@ const chapterTmpl = `
       closeChapterList();
     } else {
       chapterListPanel.style.display = 'block';
-      chapterListBtn.querySelector('span:last-child').innerHTML = '▲';
       var cur = chapterListPanel.querySelector('[data-current="1"]');
       if (cur) cur.scrollIntoView({ block: 'center' });
     }