refactor(video): replace avatar images with font awesome icons

The change replaces the avatar image tags with Font Awesome user icons to improve consistency and reduce external image dependencies.

js/video.js

@@ -154,7 +154,7 @@ function renderComments() {
     commentElement.className = 'comment-item';
     commentElement.innerHTML = `
       <div class="comment-avatar">
-        <img src="${comment.avatar}" alt="${comment.author}">
+        <i class="fas fa-user avatar-img"></i>
       </div>
       <div class="comment-content">
         <div class="comment-header">