TransferWalletBalanceRequest

{
    "senderAccountId": 1001,
    "receiverAccountId": 2002,
    "amount": 50,
    "referenceNumber": "transfer_20260506_0001",
    "nonce": "b3d9a8f2-7fb2-4f45-a22a-2c52b602ef74",
    "timestamp": 1778062500000,
    "signature": "hmac-sha256:5a7f..."
}