Update public feature details and align SEO metadata

src/app/sitemap.ts

@@ -2,36 +2,25 @@ import type { MetadataRoute } from "next";
 
 import { marketingFeatures } from "@/lib/marketing/features";
 
-function getSiteUrl() {
-  return process.env.NEXT_PUBLIC_SITE_URL ?? "https://mein-kitaplaner.de";
-}
+import { marketingLastModified, publicUrl } from "@/lib/marketing/seo";
 
 export default function sitemap(): MetadataRoute.Sitemap {
-  const siteUrl = getSiteUrl();
-  const lastModified = new Date();
-
   return [
     {
-      url: siteUrl,
-      lastModified,
-      changeFrequency: "weekly",
+      url: publicUrl(),
+      lastModified: marketingLastModified,
+      changeFrequency: "monthly",
       priority: 1,
     },
+    { url: publicUrl("/impressum"), changeFrequency: "yearly", priority: 0.2 },
     {
-      url: `${siteUrl}/impressum`,
-      lastModified,
-      changeFrequency: "yearly",
-      priority: 0.2,
-    },
-    {
-      url: `${siteUrl}/datenschutz`,
-      lastModified,
+      url: publicUrl("/datenschutz"),
       changeFrequency: "yearly",
       priority: 0.2,
     },
     ...marketingFeatures.map((feature) => ({
-      url: `${siteUrl}/features/${feature.slug}`,
-      lastModified,
+      url: publicUrl(`/features/${feature.slug}`),
+      lastModified: marketingLastModified,
       changeFrequency: "monthly" as const,
       priority: 0.8,
     })),