feat: complete MVP foundation auth and dashboard

app/dashboard/blacklist/page.tsx

@@ -0,0 +1,10 @@
+import { DashboardPlaceholderPage } from "@/components/dashboard-placeholder-page";
+
+export default function BlacklistPage() {
+  return (
+    <DashboardPlaceholderPage
+      description="Sperrlisten fuer Domains, E-Mails, Telefonnummern, Firmennamen und Place IDs folgen nach den Datenmodellen."
+      title="Blacklist"
+    />
+  );
+}