test: initial end to end test with playwright

tests/e2e/global-setup.ts

@@ -0,0 +1,18 @@
+import { TEST_ADMIN } from './scenarios/helpers';
+
+export default async function globalSetup() {
+  const res = await fetch('http://localhost:8087/api/setup', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({
+      username: TEST_ADMIN.username,
+      email:    TEST_ADMIN.email,
+      password: TEST_ADMIN.password,
+    }),
+  });
+
+  // 409 = admin already exists (idempotent across retries)
+  if (!res.ok && res.status !== 409) {
+    throw new Error(`Admin setup failed: ${res.status} ${await res.text()}`);
+  }
+}