法币充值（DEPOSIT_FIAT）

{
  "orderType": "DEPOSIT_FIAT",
  "source": { "type": "BANK_ACCOUNT", "details": { "countryCode": "US", "accountNo": "US12BANK000...IBAN", "accountName": "ACME INC", "bankName": "CHASE", "bankCode": "CHASUS33" } },
  "destination": { "type": "INTERNAL_ACCOUNT", "details": { "currency": "USD" } },
  "collectionInstrumentSelect": {
    "instrumentId": "inst_usd_master_001"
  },
  "amount": { "value": "1000.00", "currency": "USD" },
  
  "partnerOrderId": "partner_order_fiat_dep_001",
  "callbackUrl": "https://merchant.example.com/callback/order"
}

{
  "success": true,
  "data": {
    "orderId": "ord_fiat_dep_20240101_001",
    "orderType": "DEPOSIT_FIAT",
    "status": "CREATED",
    "createdAt": "2024-01-01T09:00:00Z"
  }
}