task: #3621400 Update @vardot/varbase-e2e to ^2.0.4

Moves the Varbase AI functional testing harness onto ^2.0.4, and makes the committed lock install it.

Issue: https://www.drupal.org/project/varbase_ai/issues/3621400

What changed

• package.json: "@vardot/varbase-e2e" from "^2" to "^2.0.4".
• yarn.lock: refreshed, moving the resolved harness from 2.0.3 to 2.0.4 (5 insertions, 5 deletions).

Nothing else. No step definition, feature file or selector is touched.

Why

The constraint said ^2, but the committed yarn.lock pinned the harness at 2.0.3. CI installs from the lock, so the suite stayed on the 2.0.3 steps no matter what the constraint allowed. Bumping the constraint without refreshing the lock would have changed nothing.

@vardot/varbase-e2e 2.0.4 adds 17 built-in steps and fixes one. What this project gains:

• Access assertions, so a scenario can state what a role may and may not reach.
• Page title assertions.
• An added HTTP status code phrasing.
• A fix to the existing HTTP status step. It used to re-request the URL outside the browser, losing the session cookies and following redirects, so it asserted a different request than the one under test. It is now session aware.

Test notes

The harness installs at 2.0.4, and the dry run is clean across all 9 scenarios and 30 steps — nothing ambiguous, nothing undefined. That is the evidence that none of the new 2.0.4 steps collide with anything this project defines locally.

The browser suites were not run: this change alters no step and no scenario.

AI-Generated: Yes

Checkpoints:

• File an issue
• Addition/Change/Update/Fix
• Testing to ensure no regression
• Automated unit testing coverage
• Automated functional testing coverage
• UX/UI designer responsibilities
• Readability
• Accessibility
• Performance
• Security
• Developer Documentation
• User Guide Documentation
• Reviewed by human
• Code review by maintainers
• Full testing and approval
• Credit contributors
• Review with the product owner
• Release notes snippet
• Release