Update workflow execution status

Manually update the status of a workflow execution. This is useful for programmatically controlling workflow lifecycle from external systems.

Allowed status transitions:

• ended - End the execution immediately
• handoff - Transfer execution to human agent
• waiting - Pause execution until resumed

Use cases:

• End workflows based on external events
• Transfer complex queries to human agents
• Implement custom timeout logic
• Coordinate workflows with external systems

Invalid transitions (e.g., transitioning from a terminal state) will return a 422 error with details about why the transition is not allowed.

Response: Returns full execution data including the updated status. Use GET /workflow_executions/{id} to retrieve execution context and event history.