bug: software wallet send can be swiped before the fee is shown #1744

What happened?

On the send confirmation screen, a software-wallet on-chain send can be swiped while the fee is still being refreshed, so the payment starts before its fee is shown.

SendConfirmScreen enables SwipeToConfirm on uiState.isHardwareFeeReady (SendConfirmScreen.kt:523-525), and AppViewModel.onSwipeToPay / onConfirmPay guard on the same flag. That flag is hardwareWalletId == null || (!onchainFeeUi.isLoading && !onchainFeeUi.requiresRefresh), so it is always true for a software wallet. While onchainFeeUi.isLoading, the fee cell shows its spinner, but the swipe stays enabled.

Found by reading the code during a review pass. I did not reproduce it on a device. The iOS twin now gates the swipe on fee preparation: synonymdev/bitkit-ios#1014

Expected behavior

The swipe stays disabled until the on-chain fee for the selected speed is shown, for software and hardware wallets alike.

Steps to Reproduce

1. With a software wallet, start an on-chain send and reach the confirmation screen on a slow network, so the entry fee refresh takes a few seconds.
2. Swipe while the fee cell still shows its spinner.
3. The payment proceeds without the final fee having been displayed.

Logs / Screenshots / Recordings

Code trace on master 1337f12: SendConfirmScreen.kt:523-525, AppViewModel.kt:5951 (onSwipeToPay), AppViewModel.kt:7821 (onConfirmPay), AppViewModel.kt:8957 (isHardwareFeeReady).

Bitkit Version

master 1337f12

Device / OS

Not run on a device; found by reading the code.