⚡️(e2e) unique login between tests

We will cache the login token in the browser
storage and reuse it between tests.
This will speed up the tests and reduce the
load on the server.

src/frontend/apps/e2e/__tests__/app-impress/header.spec.ts

@@ -2,9 +2,8 @@ import { expect, test } from '@playwright/test';
 
 import { keyCloakSignIn } from './common';
 
-test.beforeEach(async ({ page, browserName }) => {
+test.beforeEach(async ({ page }) => {
   await page.goto('/');
-  await keyCloakSignIn(page, browserName);
 });
 
 test.describe('Header', () => {
@@ -64,8 +63,15 @@ test.describe('Header', () => {
 
     await expect(page.getByRole('link', { name: 'Grist' })).toBeVisible();
   });
+});
+
+test.describe('Header: Log out', () => {
+  test.use({ storageState: { cookies: [], origins: [] } });
+
+  test('checks logout button', async ({ page, browserName }) => {
+    await page.goto('/');
+    await keyCloakSignIn(page, browserName);
 
-  test('checks logout button', async ({ page }) => {
     await page
       .getByRole('button', {
         name: 'My account',