When a user hits an action they can't afford (e.g. creating a QR code with
0/low balance), open an in-app two-step modal instead of bouncing them to the
central wallet page. Step 1 explains pay-as-you-go billing + shows the action
cost and current balance; step 2 takes an amount and starts a Paystack checkout
via the central identity wallet-topup API, returning the user where they were.
- service-topup-modal: rebuilt as two-step (billing explainer -> amount/pay)
- IdentityClient::walletTopup + WalletTopupController + POST /wallet/topup
- balanceGate.openTopup / qrCustomizer.redirectTopup now prefer the modal,
falling back to the wallet page only when no modal is wired
- qr-codes index + create render the modal and open it on insufficient balance
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
