Hide tab favicon on image load error

Adds an onerror handler to tab favicon images to hide them if the favicon fails to load, improving the appearance of tabs with missing or broken favicon URLs.

renderer/script.js

@@ -1029,6 +1029,9 @@ function renderTabs() {
       const icon = document.createElement('img');
       icon.src = tab.favicon;
       icon.className = 'tab-favicon';
+      icon.onerror = function() {
+        this.style.display = 'none';
+      };
       el.appendChild(icon);
     }