List secret keys in a group

{
  "group": {
    "id": "grp_123",
    "name": "api-keys",
    "description": "Third-party API keys for legal research tools"
  },
  "keys": [
    {
      "key": "LEXIS_API_KEY",
      "createdAt": "2024-01-15T10:30:00Z",
      "updatedAt": "2024-01-15T10:30:00Z"
    },
    {
      "key": "WESTLAW_ACCESS_TOKEN",
      "createdAt": "2024-01-16T14:20:00Z",
      "updatedAt": "2024-01-20T09:15:00Z"
    }
  ]
}