fix: lnurl navigating to the next step before ui update

[jvsena42]

Closes #418

Description

1. When pasting an LNURL-withdraw with equal min/max amounts, the code updates state and immediately navigates
2. The navigation happens before the UI has recomposed with the new state values
3. The WithdrawConfirmScreen expects uiState.amount to be set, but may see stale data
4. This causes the app to appear frozen or unresponsive

The fix:

• Add a small delay before navigation (using existing TRANSITION_SCREEN_MS constant)
• This gives the UI time to recompose with correct state

Preview

QA Notes

• Connect to external node -> create a LNURL withdraw with minWithdrawable == maxWithdrawable -> paste in the app

[Copilot]

Pull request overview

This PR fixes a race condition in the LNURL-withdraw flow where navigation occurs before the UI has time to recompose with updated state values. When an LNURL-withdraw request has equal minimum and maximum amounts, the code was immediately navigating to the confirmation screen before the UI could reflect the new state, causing the app to appear frozen or unresponsive.

Key Changes:

• Added a coroutine-based delay before navigation in the LNURL-withdraw handler
• Uses the existing TRANSITION_SCREEN_MS constant to ensure UI recomposition completes

[jvsena42]

@piotr-iohk Does this PR unblock some E2E flow? like lnurl_1 from the issue

[jvsena42]

Couldn't decode the lnurl invoices locally, but it is passing on E2E, so I suppose it is something in my setup

2026-01-05 08:27:56.123  7761-7799  APP                     to.bitkit.dev                        E  2026-01-05 11:27:56.123 ERROR   [AppViewModel.kt:714]                Failed to decode scan data: 'lnurl1dp68gup69uhkcmmrv9kxsmmnwsarxvpsxqhhqcte9a3nyd35xa3r2enrxqcnydtzx5ckzer9xumrgvmxx5ekxcm9x5crg2wwcny' [InvalidFormat=''] - AppViewModel
                                                                                                    com.synonym.bitkitcore.DecodingException$InvalidFormat: 
                                                                                                    	at com.synonym.bitkitcore.FfiConverterTypeDecodingError.read-0Q8s1zI(bitkitcore.android.kt:6622)
                                                                                                    	at com.synonym.bitkitcore.FfiConverterTypeDecodingError.read-0Q8s1zI(bitkitcore.android.kt:6619)
                                                                                                    	at com.synonym.bitkitcore.FfiConverter$DefaultImpls.liftFromRustBuffer(bitkitcore.android.kt:231)
                                                                                                    	at com.synonym.bitkitcore.FfiConverterRustBuffer$DefaultImpls.liftFromRustBuffer(bitkitcore.android.kt:243)
                                                                                                    	at com.synonym.bitkitcore.FfiConverterTypeDecodingError.liftFromRustBuffer(bitkitcore.android.kt:6619)
                                                                                                    	at com.synonym.bitkitcore.FfiConverterTypeDecodingError.liftFromRustBuffer(bitkitcore.android.kt:6619)
                                                                                                    	at com.synonym.bitkitcore.FfiConverterRustBuffer$DefaultImpls.lift(bitkitcore.android.kt:244)
                                                                                                    	at com.synonym.bitkitcore.FfiConverterTypeDecodingError.lift(bitkitcore.android.kt:6619)
                                                                                                    	at com.synonym.bitkitcore.FfiConverterTypeDecodingError.lift(bitkitcore.android.kt:6619)
                                                                                                    	at com.synonym.bitkitcore.DecodingExceptionErrorHandler.lift(bitkitcore.android.kt:6616)
                                                                                                    	at com.synonym.bitkitcore.DecodingExceptionErrorHandler.lift(bitkitcore.android.kt:6615)
                                                                                                    	at com.synonym.bitkitcore.Bitkitcore_androidKt.uniffiCheckCallStatus(bitkitcore.android.kt:294)
                                                                                                    	at com.synonym.bitkitcore.Bitkitcore_androidKt$uniffiRustCallAsync$2$invokeSuspend$$inlined$uniffiRustCallWithError$1.invoke(bitkitcore.android.kt:284)
                                                                                                    	at com.synonym.bitkitcore.Bitkitcore_androidKt$uniffiRustCallAsync$2$invokeSuspend$$inlined$uniffiRustCallWithError$1.invoke(bitkitcore.android.kt:282)
                                                                                                    	at com.synonym.bitkitcore.UniffiRustCallStatusHelper.withReference$lib_release(bitkitcore.android.kt:382)
                                                                                                    	at com.synonym.bitkitcore.Bitkitcore_androidKt$uniffiRustCallAsync$2.invokeSuspend(bitkitcore.android.kt:11561)
                                                                                                    	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:34)
                                                                                                    	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:100)
                                                                                                    	at kotlinx.coroutines.internal.LimitedDispatcher$Worker.run(LimitedDispatcher.kt:124)
                                                                                                    	at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:89)
                                                                                                    	at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:586)
                                                                                                    	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:820)
                                                                                                    	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:717)
                                                                                                    	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:704)

[piotr-iohk]

@piotr-iohk is this code still necessary for testing? the app could read the string directly from clipboard https://github.com/synonymdev/bitkit-android/blob/c96bc1f37fb30eccbdb9b051ea12ed9f949f191f/app/src/main/java/to/bitkit/ui/screens/scanner/QrScanningScreen.kt#L337C1-L367C10

Yes, it was like that in the RN app, therefore it was ported. I guess the idea was to go through the Qr screening flow.

[ovitrif]

Small nit.

[ovitrif]

utAck.

Will test later today but you can already merge.

All LGTM, if required changes are identified after testing, we can always fix later.