Add a header ad component to various pages across the platform

Introduce a new `HeaderAd` component for displaying AdSense ads on multiple pages, including `FolxStadlPage`, `GeschichteLiedPage`, `GipfelstammtischPage`, `Impressum`, `LivePage`, `PrivacyPolicy`, `TermsOfService`, `VideoPage`, `admin`, `home`, and `not-found`. This component is implemented in `client/src/components/HeaderAd.tsx` and integrated into the respective page components.

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/HUI2eAX

client/src/pages/home.tsx

@@ -6,6 +6,7 @@ import { Link } from "wouter";
 import { Input } from "@/components/ui/input";
 import { Search, Menu, X } from "lucide-react";
 import AdSenseAd from "@/components/adsense-ad";
+import HeaderAd from "@/components/HeaderAd";
 
 interface VideosResponse {
   videos: Video[];
@@ -208,6 +209,9 @@ export default function Home() {
         )}
       </div>
 
+      {/* Fixed Header Ad */}
+      <HeaderAd />
+
       {/* Header Banner Ad */}
       <div className="container py-4 border-b border-white/10">
         <div className="w-full flex justify-center">