Add various ad placements throughout the website to monetize content

Integrates AdSense for ads on the homepage, article pages, and video pages, including in-feed ads styled as article cards.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 413891e8-d784-4bea-b9f5-91a5a68316b4
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: b587b746-f67b-4539-9958-86999aee56de
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/f209e72a-0939-48fa-84fc-57854de71967/413891e8-d784-4bea-b9f5-91a5a68316b4/igVW4lQ
Replit-Helium-Checkpoint-Created: true

client/src/pages/videos.tsx

@@ -7,6 +7,7 @@ import { Play, ArrowLeft } from "lucide-react";
 import { Skeleton } from "@/components/ui/skeleton";
 import Header from "@/components/header";
 import Footer from "@/components/footer";
+import { ArticleCardAd } from "@/components/adsense";
 
 function VideoCard({ article }: { article: Article }) {
   const thumbSrc = article.coverImage
@@ -83,9 +84,15 @@ export default function VideosPage() {
           </div>
         ) : articles && articles.length > 0 ? (
           <div className="grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 lg:grid-cols-4 gap-5">
-            {articles.map((article) => (
-              <VideoCard key={article.id} article={article} />
-            ))}
+            {articles.flatMap((article, index) => {
+              const items = [
+                <VideoCard key={article.id} article={article} />,
+              ];
+              if (index === 2) {
+                items.push(<ArticleCardAd key="ad-video-1" />);
+              }
+              return items;
+            })}
           </div>
         ) : (
           <div className="text-center py-16">