Show file sizes in list

Include mp3 size display in API responses and render it in the list; remove obsolete Apache config.

client/static/app.js

@@ -84,7 +84,9 @@ function renderList() {
     }
 
     const label = document.createElement("span");
-    label.textContent = item.display_time;
+    label.textContent = item.size_display
+      ? `${item.display_time} (${item.size_display})`
+      : item.display_time;
     label.className = "item-label";
     li.appendChild(label);