chore: add basic acceptance tests

acceptance/tests/admin.spec.ts

@@ -0,0 +1,7 @@
+import {test} from "@playwright/test";
+import {loginWithPassword} from "./login";
+
+test("admin login", async ({page}) => {
+    await loginWithPassword(page, "zitadel-admin@zitadel.localhost", "Password1.")
+    await page.getByRole("heading", {name: "Welcome ZITADEL Admin!"}).click();
+});