server side and user client side completed for registration

server/api/v1/admin/auth/invitation/index.get.ts

@@ -0,0 +1,9 @@
+import prisma from "~/server/internal/db/database";
+
+export default defineEventHandler(async (h3) => {
+  const user = await h3.context.session.getAdminUser(h3);
+  if (!user) throw createError({ statusCode: 403 });
+
+  const invitations = await prisma.invitation.findMany({});
+  return invitations;
+});