Cancel an order

Any authorized caller may cancel while awaiting_payment. The API key that CREATED the order may also cancel it while confirmed or printing — stopping production before the press finishes. shipped and delivered can never be canceled; that is a refund conversation, not a cancel. Canceling moves no money, and it RELEASES the order's client_reference: replaying that reference afterwards creates a new order and prints it. If the order changes status before the cancel lands, the answer is 409 not_cancellable naming the status it moved to — a cancel never reports success it did not achieve. The same two tiers apply to the MCP cancel_order tool.