feat(Sitemap, SEO): update sitemap generation and SEO configurations

- Enhanced update-sitemap.sh to generate a new sitemap structure with lastmod dates for additional URLs.
- Updated SEO configurations in server.js and seo.js to allow indexing for impressum and datenschutz pages.
- Introduced a list of noindex prefixes to manage SEO settings dynamically based on route paths.
- Added structured FAQ schema in index.html to improve search engine visibility and user engagement.

update-sitemap.sh

@@ -15,8 +15,38 @@ fi
 
 echo "Aktualisiere lastmod-Datum auf: $TODAY"
 
-# Ersetze alle lastmod-Daten mit dem heutigen Datum
-sed -i "s/<lastmod>.*<\/lastmod>/<lastmod>${TODAY}<\/lastmod>/g" "$SITEMAP_FILE"
+URLS=(
+  "https://tt-tagebuch.de/"
+  "https://tt-tagebuch.de/impressum"
+  "https://tt-tagebuch.de/datenschutz"
+)
+
+cat > "$SITEMAP_FILE" <<EOF
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9
+        http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
+  <url>
+    <loc>${URLS[0]}</loc>
+    <lastmod>${TODAY}</lastmod>
+    <changefreq>weekly</changefreq>
+    <priority>1.0</priority>
+  </url>
+  <url>
+    <loc>${URLS[1]}</loc>
+    <lastmod>${TODAY}</lastmod>
+    <changefreq>yearly</changefreq>
+    <priority>0.3</priority>
+  </url>
+  <url>
+    <loc>${URLS[2]}</loc>
+    <lastmod>${TODAY}</lastmod>
+    <changefreq>yearly</changefreq>
+    <priority>0.3</priority>
+  </url>
+</urlset>
+EOF
 
 echo "✓ Sitemap aktualisiert"
 echo ""
@@ -31,4 +61,3 @@ echo "   -> URL eingeben: https://tt-tagebuch.de/sitemap.xml"
 echo ""
 echo "3. Sitemap testen:"
 echo "   curl https://tt-tagebuch.de/sitemap.xml"
-