Add Playwright e2e coverage and Node 20 pin

frontend/e2e/auth.spec.ts

@@ -0,0 +1,13 @@
+import { expect, test } from '@playwright/test'
+import { signIn } from './helpers/auth'
+
+test.use({ storageState: { cookies: [], origins: [] } })
+
+test.describe('authentication smoke tests', () => {
+  test('team admin can sign in through the login form', async ({ page }) => {
+    await signIn(page)
+
+    await expect(page).toHaveURL(/\/$/)
+    await expect(page.getByTestId('app-shell')).toBeVisible()
+  })
+})