{
  "model_driven_without_gate": {
    "candidate": {
      "kind": "write",
      "resource": "order_demo",
      "value": "refunded"
    },
    "policy": {
      "allowed": false,
      "reason": "approval_required"
    },
    "terminal": "blocked"
  },
  "graph_driven_with_gate": {
    "trace": [
      {
        "node": "read_order",
        "status": "completed"
      },
      {
        "node": "request_approval",
        "status": "approved"
      },
      {
        "node": "write_refund",
        "status": "completed"
      }
    ],
    "terminal": "success"
  }
}