{
  "item_id": "ITEM-101",
  "name": "主链路网络健康探活",
  "status": "PASS",
  "latency_ms": 140,
  "steps": [
    { "step": 1, "action": "dns_lookup", "status": "ok" },
    { "step": 2, "action": "tcp_ping", "status": "ok", "rtt_ms": 12 },
    { "step": 3, "action": "health_endpoint", "status": "200_OK" }
  ],
  "metadata": {
    "cluster": "ap-east-01",
    "trace_id": "tr-abc123456"
  }
}