Cancel a running evaluation (Kubernetes Job cancellation + workflow status update).
Cancels an evaluation that is in progress (CREATED, STARTING, or RUNNING status). This will:
Args: evaluation_id: UUID of the evaluation to cancel claims: JWT claims with user and team info diamond_domain: Diamond domain orchestrator storage: Evaluation storage adapter
Returns: Status dict with “cancelled” status
Raises: HTTPException: 404 if evaluation not found, 400 if evaluation is already completed/cancelled