Update ad sizes and placement for improved user experience

Update the `HeaderAd.tsx` component to use a 970x90px desktop ad slot and adjust the `home.tsx` page to display the same ad size before the footer.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 45a1dcfc-f8a2-475a-a6b9-96fbb841dc27
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/60d372ff-2c10-46c7-b01b-10c3435136b0/45a1dcfc-f8a2-475a-a6b9-96fbb841dc27/RzcERJv

client/src/pages/home.tsx

@@ -221,12 +221,12 @@ export default function Home() {
         </div>
       </main>
 
-      {/* Desktop Bottom Banner Ad */}
+      {/* Desktop Bottom Banner Ad - 970x90 before footer */}
       <div className="container py-4 border-t border-white/10 hidden md:block">
         <div className="w-full flex justify-center">
           <AdSenseAd 
-            adSlot="5972813417"
-            width={728}
+            adSlot="6554928035"
+            width={970}
             height={90}
             className="max-w-full"
             lazy={true}