Transaction Flow — iPhone

1. App creates a CyoGateTransactionRequest
2. SDK activates NFC and shows payment prompt
3. Customer taps card/device
4. NFC reads and generates transaction cryptogram
5. SDK sends to CyoGate gateway
6. Gateway returns approved/declined response
7. App shows result and receipt

let request = CyoGateTransactionRequest(
    amount: 29.99, currency: "USD", type: .sale,
    orderID: "ORDER-\(UUID().uuidString)", description: "Coffee"
)
transactionManager.startTransaction(request: request) { result in
    DispatchQueue.main.async {
        switch result {
        case .approved(let txn): self?.showSuccess(transactionID: txn.transactionID)
        case .declined(let r):   self?.showDecline(reason: r)
        case .error(let e):      self?.showError(error: e)
        }
    }
}