✨(app-desk) create mails feature

Create the archi to handle the mails feature.
It has a different layout than the other features,
we don't display the sidebar to keep the
user focused on the mail content.

src/frontend/apps/e2e/__tests__/app-desk/menu.spec.ts

@@ -10,6 +10,7 @@ test.beforeEach(async ({ page, browserName }) => {
 test.describe('Menu', () => {
   const menuItems = [
     { name: 'Search', isDefault: true },
+    { name: 'Mails', isDefault: false },
     { name: 'Favorite', isDefault: false },
     { name: 'Recent', isDefault: false },
     { name: 'Contacts', isDefault: false },