Fix video thumbnail display issues and improve category row rendering

Corrected an "Invalid hook call" warning by ensuring the key prop is applied to the outermost element in the video mapping of the CategoryRow component in `netflix-grid.tsx`.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 401e2ec0-e00d-4f10-9d0e-60f3d479f9a5
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: b8a18225-2a77-4482-93d7-b918832f4401
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/60d372ff-2c10-46c7-b01b-10c3435136b0/401e2ec0-e00d-4f10-9d0e-60f3d479f9a5/QA9iJJ7

client/src/components/netflix-grid.tsx

@@ -433,7 +433,6 @@ function CategoryRow({ category, onVideoClick, hideScrollButtons = false }: Cate
           onTouchEnd={handleTouchEnd}
         >
           {category.videos.map((video, index) => (
-            <>
             <div 
               key={video.id} 
               className="flex-shrink-0 w-[calc(100vw-1.5rem)] sm:w-[330px] relative hover:z-50"
@@ -463,8 +462,6 @@ function CategoryRow({ category, onVideoClick, hideScrollButtons = false }: Cate
                 className="w-full hover:scale-102 md:hover:scale-105 hover:z-50 transition-all duration-300 md:duration-500 hover:shadow-2xl rounded-lg overflow-hidden"
               />
             </div>
-              
-            </>
           ))}
         </div>