[Alias] Brent futures curve — use /v1/futures/brent

Example response

{
  "status": "success",
  "data": {
    "spot": 82.45,
    "contracts": [
      {
        "month": "M1",
        "contract_date": "2025-02",
        "price": 82.3,
        "volume": 125000,
        "open_interest": 450000
      }
    ],
    "curve_structure": "backwardation"
  }
}