Implement CI/CD Pipeline with Automated Testing

Establish automated testing pipeline to ensure code quality and prevent regressions. The existing .gitlab-ci.yml needs to be configured for proper test execution.

Acceptance Criteria:

• Configure GitLab CI/CD pipeline for automated testing
• Add PHP 8.2+ testing environment
• Run test suite on every merge request
• Generate and publish test coverage reports
• Add code quality checks (PHP_CodeSniffer, PHPStan)
• Implement automated dependency security scanning

Related Files:

• .gitlab-ci.yml (update/enhance)
• composer.json (add dev dependencies if needed)