Module plan_step_event 

Plan-step execution event.

PlanStepEvent is the runtime bridge between immutable planning structure and actual execution.

How to use this object

• Append a new event whenever a logical plan step changes execution state inside a run.
• Use consumed_frames and produced_frames to document context flow.
• Set spawned_task_id when the step delegates work to a durable Task.
• Set outputs when the step produced structured runtime output.

How it works with other objects

• plan_id points to the immutable Plan revision.
• step_id points to the stable PlanStep.step_id.
• run_id ties the execution fact to the specific attempt.
• ContextFrame IDs describe what context the step consumed and produced.

How Libra should call it

Libra should reconstruct current step state from the ordered PlanStepEvent stream rather than mutating PlanStep inside the stored plan snapshot.

Structs

PlanStepEvent

Append-only execution fact for one logical plan step in one Run.

Enums

PlanStepStatus