Native 'Rollback' or 'Cleanup' triggers for CI stages to handle orphaned artifacts.

Currently, PipelineRollback in CI stages lacks a native mechanism to revert external side effects—like published NPM packages—if a subsequent step fails or the pipeline is aborted. Providing a native cleanup trigger for non-deployment steps would prevent registry inconsistency and ensure that "in-flight" abortions don't leave behind orphaned package versions.