🥅(app-desk) better error management

We don't know how the error body returned by the
api will be, so we handle it in a more generic way.

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

@@ -95,6 +95,25 @@ test.describe('Teams Create', () => {
     await expect(page).toHaveURL(/\/teams$/);
   });
 
+  test('checks error when duplicate team', async ({ page, browserName }) => {
+    const panel = page.getByLabel('Teams panel').first();
+
+    await panel.getByRole('button', { name: 'Add a team' }).click();
+
+    const teamName = `My duplicate team ${browserName}-${Math.floor(Math.random() * 1000)}`;
+    await page.getByText('Team name').fill(teamName);
+    await page.getByRole('button', { name: 'Create the team' }).click();
+
+    await panel.getByRole('button', { name: 'Add a team' }).click();
+
+    await page.getByText('Team name').fill(teamName);
+    await page.getByRole('button', { name: 'Create the team' }).click();
+
+    await expect(
+      page.getByText('Team with this Slug already exists.'),
+    ).toBeVisible();
+  });
+
   test('checks 404 on teams/[id] page', async ({ page }) => {
     await page.goto('/teams/some-unknown-team');
     await expect(page.getByText('404 - Page not found')).toBeVisible({