Add automated functional acceptance testing for Canvas Override with webship-js (Playwright + Cucumber-js), Drupal Core + Drupal CMS support, and MkDocs documentation

Problem/Motivation

The Canvas Override module currently has no automated functional acceptance test coverage. Core functionality is only validated through manual testing, which increases the risk of regressions when changes are made to override behavior, Canvas integrations, configuration workflows, and user-facing functionality.

In addition, the project does not currently provide a standardized testing framework that can be executed locally, in CI pipelines, or against both Drupal Core and Drupal CMS installations. Documentation for setting up, running, and extending automated tests is also limited.

Proposed resolution

Add a complete automated functional acceptance testing framework for Canvas Override using webship-js with Playwright and Cucumber-js.

• Add webship-js testing infrastructure and project configuration.
• Add Playwright browser automation support.
• Add Cucumber-js feature specifications and step definitions.
• Add automated test coverage for Canvas Override functionality and user workflows.
• Add support for testing against both Drupal Core and Drupal CMS installations.
• Add reusable test fixtures, helpers, and configuration files.
• Add CI-ready test execution commands and reporting.
• Add MkDocs documentation covering installation, configuration, test execution, development workflow, and contribution guidelines.
• Provide example feature files and documentation for creating additional acceptance tests.

This will provide repeatable end-to-end testing, reduce regression risk, improve contributor experience, and establish a foundation for future automated quality assurance efforts.

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
• ✅ Documentation
• ✅ Code review by maintainers
• ✅ Full testing and approval
• ✅ Credit contributors
• ✅ Review with the product owner
• ✅ Release notes snippet
• ✅ Release varbase-11.0.0-beta1, canvas_override-1.0.0-beta1

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• ci: #3594223 Add automated functional acceptance testing for Canvas Override with webship-js (Playwright + Cucumber-js), Drupal Core + Drupal CMS support, and MkDocs documentation