Alpha 5: PHPCS + PHPStan pipeline, property override fixes - Added PHPCS (Drupal/DrupalPractice) and PHPStan to CI pipeline - Fixed readonly property override errors (AgentCheckoutController, AgentTokenRevokeForm) - Bumped CI to PHP 8.3 for Drupal 11.3 compatibility - All 200 tests passing, 0 PHPCS errors, 0 PHPStan errors