Remove ad integrations from various platform pages

Refactor HeaderAd and VideoPage components to remove AdSenseAd integrations and adjust header ad container.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 401e2ec0-e00d-4f10-9d0e-60f3d479f9a5
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/60d372ff-2c10-46c7-b01b-10c3435136b0/401e2ec0-e00d-4f10-9d0e-60f3d479f9a5/3l7HcE7

client/src/components/HeaderAd.tsx

@@ -21,7 +21,7 @@ export default function HeaderAd() {
   }, []);
 
   return (
-    <div className="w-full flex justify-center py-1 bg-bunny-dark hidden md:block" ref={adRef}>
+    <div className="hidden lg:flex justify-center py-4" ref={adRef}>
       {/* Desktop Only: 970x90px Header Ad */}
       <ins 
         className="adsbygoogle"