task: Switch the Varbase functional testing suite to Varbase E2E on 9.2.x

Problem/Motivation

The Varbase functional testing suite on this branch still depends on the previous testing package. The harness now ships as Varbase E2E (@vardot/varbase-e2e 2.0.0), which includes the Drupal and Varbase step packs as built-ins. Keeping local copies makes scenarios ambiguous and cuts this project off from upstream fixes.

Steps to reproduce

Run grep -rn "VARBASE_E2E\|varbase-e2e" package.json cucumber.js on 9.2.x — it still points at the previous package.

Proposed resolution

• Depend on @vardot/varbase-e2e ^2.0.0; update cucumber.js require globs and the report script path.
• Re-point custom step helper imports at the new package.
• Remove custom steps now shipped as built-ins; keep only project-specific ones.
• Rename env vars to the VARBASE_E2E_* family across config/CI/DDEV.
• Verify with npx cucumber-js --dry-run (zero ambiguous/undefined), then CI.

AI-Generated: Yes

Remaining tasks

• ✅ 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

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• The Varbase functional testing suite now runs on Varbase E2E (@vardot/varbase-e2e 2.0.0).