feat: add migration to mark userful instances installation completed

packages/backend/src/db/migrations/20240507135944_mark_userful_instances_installation_completed.js

@@ -0,0 +1,17 @@
+export async function up(knex) {
+  const users = await knex('users').limit(1);
+
+  // no user implies installation is not completed yet.
+  if (users.length === 0) return;
+
+  await knex('config').insert({
+    key: 'installation.completed',
+    value: {
+      data: true
+    }
+  });
+};
+
+export async function down(knex) {
+  await knex('config').where({ key: 'installation.completed' }).delete();
+};