fix: Add 'use client' to impressum page for onClick handlers

src/app/impressum/page.tsx

@@ -1,12 +1,8 @@
-import { Metadata } from 'next';
+'use client';
+
 import { ArrowLeft, Mail, Phone, MapPin, Building2, User, FileText } from 'lucide-react';
 import Link from 'next/link';
 
-export const metadata: Metadata = {
-    title: 'Impressum',
-    description: 'Impressum und rechtliche Angaben',
-};
-
 /**
  * Bot-proof Impressum page
  * Contact info is rendered via CSS/JS to prevent simple scraping