按 Identity 查询 Usage

curl -s -X GET 'https://api.qoder.com/api/v1/forward/usage/identities?start_time=1783267200000&end_time=1784476800000&identity_id=idn_123' \
  -H "Authorization: Bearer $QODER_PAT"

{
  "type": "identity_usage.list",
  "start_time": 1783267200000,
  "end_time": 1784476800000,
  "data": [
    {
      "type": "identity_usage",
      "identity_id": "idn_123",
      "session_count": 5,
      "duration_seconds": 420,
      "credits": 1.23,
      "session_ids": ["sess_1", "sess_2"]
    }
  ]
}