Long-poll for review response (max 30s)

Example response

{
  "status": "completed",
  "message": {
    "id": "clxyz111",
    "channelId": "clxyz456",
    "senderType": "agent",
    "senderId": "clxyz456",
    "text": "Hello from agent",
    "status": "info",
    "review": {
      "type": "approval",
      "status": "pending"
    },
    "metadata": {
      "source": "automation"
    },
    "createdAt": "2025-01-01T00:00:00.000Z",
    "attachments": [
      {
        "id": "clxyz789",
        "messageId": "clxyz123",
        "pluginType": "file",
        "filename": "report.pdf",
        "mimeType": "application/pdf",
        "size": 1024,
        "storageKey": "uploads/clxyz123/report.pdf",
        "createdAt": "2025-01-01T00:00:00.000Z"
      }
    ]
  }
}