Mermaid

```mermaid
stateDiagram-v2
[*] --> SCHEDULED: Start
SCHEDULED --> STARTED: Worker picks up task

SCHEDULED --> CANCEL_REQUESTED: RequestCancel
STARTED --> CANCEL_REQUESTED: RequestCancel
CANCEL_REQUESTED --> CANCEL_REQUESTED: RequestCancel

CANCEL_REQUESTED --> CANCELED: RespondCanceled
CANCEL_REQUESTED --> COMPLETED: RespondCompleted
CANCEL_REQUESTED --> FAILED: RespondFailed
CANCEL_REQUESTED --> TERMINATED: Terminate
CANCEL_REQUESTED --> TIMED_OUT: Timeout

SCHEDULED --> CANCELED: RequestCancel (immediate)
```

The issue contains only a Mermaid state diagram and names no file, test, or entry point. Clarify where the diagram belongs and what documentation change is expected before work can begin.

Written by the indexing model from the issue text.