Register a versioned workflow, start it through WorkflowExecutor, and inspect
its execution before changing behavior. Additive output changes are normally
safe; renamed inputs, removed outputs, and changed task references are breaking
and require a new workflow version.
Use pause/resume for controlled maintenance, retry only transient failures, and terminate executions with an explicit reason. Inspect failed tasks before retrying to avoid replaying unsafe side effects. See WORKFLOW.md for the complete lifecycle API.