Cancel Order (Web v1)

Rocky impl: DELETE /v1/orders/{order_id} ✓

Web v1 native — counterpart to Web v1 place-order.

Request

DELETE /v1/orders/{order_id}?user_id={user_id}

order_id is the UUID returned by place-order. Returns 204 No Content on success.

Errors: 400 malformed UUID, 403 order belongs to a different user, 404 order not found.