Initial commit: Kalendartool (Next.js, Prisma, Docker)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

app/admin/users/page.tsx

@@ -0,0 +1,25 @@
+/**
+ * Admin: Benutzerverwaltung (Option B).
+ * Nur ADMIN-Rolle hat Zugriff; USER werden zurueck zum Dashboard geleitet.
+ */
+import { redirect } from 'next/navigation';
+import { requireDbUser } from '@/lib/api/context';
+import { UserManagement } from '@/components/admin/UserManagement';
+import { AppShell } from '@/components/layout/AppShell';
+
+export default async function AdminUsersPage() {
+  const user = await requireDbUser().catch(() => null);
+  if (!user) {
+    redirect('/login');
+  }
+  if (user.role !== 'ADMIN') {
+    redirect('/dashboard');
+  }
+
+  return (
+    <AppShell role={user.role} userEmail={user.email} username={user.username}>
+      <h1 className="mb-6 text-2xl font-bold">Benutzerverwaltung</h1>
+      <UserManagement currentUserId={user.id} />
+    </AppShell>
+  );
+}