Improve media loading performance for posts by enabling lazy loading

Added 'loading="lazy"' attribute to media elements in the new-post page to optimize image and video loading.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ae4037a0-2a6f-4530-9bac-79b543286bda
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/397bca8c-984f-43ff-841a-10897aeb8140/ae4037a0-2a6f-4530-9bac-79b543286bda/F3F3s9V

client/src/pages/new-post.tsx

@@ -78,6 +78,7 @@ function SortableMediaItem({
           src={media.facebookFeedUrl || media.originalUrl} 
           alt={media.fileName}
           className="w-full h-full object-cover"
+          loading="lazy"
         />
       </button>
       {isSelected && (
@@ -513,6 +514,7 @@ export default function NewPost() {
                                     src={media.facebookFeedUrl || media.originalUrl} 
                                     alt={media.fileName}
                                     className="w-full h-full object-cover"
+                                    loading="lazy"
                                   />
                                   {isSelected && (
                                     <div className="absolute inset-0 bg-primary/10 flex items-center justify-center">