feat: Add comprehensive SEO implementation

- Add robots.txt with admin/API blocking
- Add dynamic sitemap.xml with static pages and genre pages
- Implement full meta tags (Open Graph, Twitter Cards, Canonical, Alternates)
- Add SEO helper functions for domain detection and URL generation
- Add generateMetadata to all pages (homepage, about, genre, special)
- Support automatic domain detection for hoerdle.de and hördle.de
- Add SEO configuration to lib/config.ts

app/[locale]/page.tsx

@@ -7,15 +7,33 @@ import { Link } from '@/lib/navigation';
 import { PrismaClient } from '@prisma/client';
 import { getTranslations } from 'next-intl/server';
 import { getLocalizedValue } from '@/lib/i18n';
+import { generateBaseMetadata } from '@/lib/metadata';
+import type { Metadata } from 'next';
 
 export const dynamic = 'force-dynamic';
 
 const prisma = new PrismaClient();
 
+export async function generateMetadata({ params }: { params: Promise<{ locale: string }> }): Promise<Metadata> {
+    const { locale } = await params;
+    const t = await getTranslations('Home');
+    
+    // Get localized title and description
+    const title = locale === 'de' 
+        ? 'Hördle - Tägliches Musik-Erraten'
+        : 'Hördle - Daily Music Guessing Game';
+    
+    const description = locale === 'de'
+        ? 'Spiele Hördle und errate Songs aus kurzen Audio-Clips! Täglich neue Rätsel aus verschiedenen Genres. Inspiriert von Wordle, aber für Musikfans.'
+        : 'Play Hördle and guess songs from short audio clips! Daily new puzzles from various genres. Inspired by Wordle, but for music lovers.';
+    
+    return await generateBaseMetadata(locale, '', title, description);
+}
+
 export default async function Home({
     params
 }: {
-    params: { locale: string };
+    params: Promise<{ locale: string }>;
 }) {
     const { locale } = await params;
     const t = await getTranslations('Home');