Fix missing quotes in getElementById call

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/static/js/app.js

@@ -636,7 +636,7 @@ const App = {
         if (inc) this._announceForSR('Lage ausgewählt: ' + inc.title);
         this.renderSidebar();
 
-        var mc = document.getElementById(main-content);
+        var mc = document.getElementById("main-content");
         mc.scrollTop = 0;
 
         document.getElementById('empty-state').style.display = 'none';