Optimize merge queue to only run E2E and integrate prettier into lint (#18459)

## Summary

- **Merge queue optimization**: Created a dedicated
`ci-merge-queue.yaml` workflow that only runs Playwright E2E tests on
`ubuntu-latest-8-cores`. Removed `merge_group` trigger from all 7
existing CI workflows (front, server, shared, website, sdk, zapier,
docker-compose). The merge queue goes from ~30+ parallel jobs to a
single focused E2E job.
- **Label-based merge queue simulation**: Added `run-merge-queue` label
support so developers can trigger the exact merge queue E2E pipeline on
any open PR before it enters the queue.
- **Prettier in lint**: Chained `prettier --check` into `lint` and
`prettier --write` into `lint --configuration=fix` across `nx.json`
defaults, `twenty-front`, and `twenty-server`. Prettier formatting
errors are now caught by `lint` and fixed by `lint:fix` /
`lint:diff-with-main --configuration=fix`.

## After merge (manual repo settings)

Update GitHub branch protection required status checks:
1. Remove old per-workflow merge queue checks (`ci-front-status-check`,
`ci-e2e-status-check`, `ci-server-status-check`, etc.)
2. Add `ci-merge-queue-status-check` as the required check for the merge
queue

packages/twenty-e2e-testing/tests/authentication/signup_invite_email.spec.ts

@@ -34,7 +34,7 @@ test('Sign up with invite link via email', async ({
   });
 
   await test.step('Create new account', async () => {
-    await loginPage.clickLoginWithEmail();
+    await loginPage.clickLoginWithEmailIfVisible();
     await loginPage.typeEmail(email);
     await loginPage.clickContinueButton();
     await loginPage.typePassword(process.env.DEFAULT_PASSWORD);