fix: fallback expired Bolt 11 to on-chain on unified invoice

[jvsena42]

Description

• Fallback to on-chain on unified invoice when Bolt11 is expired
• Navigation bug when scanning invalid Bolt 11. Was navigating to amount screen even without a valid on-chain address
• Added Address/balance validation on 'Send Bitcoin' #328 checks for manual and pasting

Linked Issues/Tasks

Fix #300
Fix #328

Screenshot / Video

uniffied-expired-no-amount.mp4

invalid-input.mp4

wrong-network.mp4

fallback-to-sagings.mp4

unsuficcient-spending-failsback-to-onchain.mp4

ln-only-expired-and-insufficient-spending.mp4

expired-insufficient-savings.mp4

[Copilot]

Pull request overview

This PR fixes the handling of expired Bolt 11 invoices in unified invoices by implementing a fallback to on-chain payment when the Lightning invoice has expired. It also addresses a navigation bug where the app would incorrectly navigate to the amount screen even when scanning an invalid Bolt 11 invoice without a valid on-chain address.

Changes:

• Added expiration checks for Lightning invoices in unified invoice handling with fallback to on-chain when expired
• Fixed navigation logic to prevent navigation when no valid invoice data exists
• Added expiration validation for standalone Lightning invoices

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
Bitkit/ViewModels/AppViewModel.swift	Added expiration checks for Lightning invoices with on-chain fallback logic in unified invoice handling
Bitkit/Utilities/PaymentNavigationHelper.swift	Changed return type to optional and added validation to prevent navigation without valid invoice data
Bitkit/Views/Wallets/Send/SendEnterManuallyView.swift	Updated to handle optional navigation route from PaymentNavigationHelper
Bitkit/Views/Wallets/Send/SendConfirmationView.swift	Added expiration check before processing Lightning payments

[ben-kaufman]

utAck, changes look good

[ovitrif]

Tested by applying this patch to Android app and then creating an invoice and paying it from iOS:

diff --git a/app/src/main/java/to/bitkit/repositories/LightningRepo.kt b/app/src/main/java/to/bitkit/repositories/LightningRepo.kt
index 791204e6..8c39d85c 100644
--- a/app/src/main/java/to/bitkit/repositories/LightningRepo.kt
+++ b/app/src/main/java/to/bitkit/repositories/LightningRepo.kt
@@ -574,7 +574,7 @@ class LightningRepo @Inject constructor(
     suspend fun createInvoice(
         amountSats: ULong? = null,
         description: String,
-        expirySeconds: UInt = 86_400u,
+        expirySeconds: UInt = 20u,
     ): Result<String> = executeWhenNodeRunning("createInvoice") {
         updateGeoBlockState()
         val invoice = lightningService.receive(amountSats, description, expirySeconds)

[pwltr]

Mostly good, please check with the react native app for the correct UX for these cases:

• 0 balance -> should show "Insufficient Savings" toast (more relevant)
• 0 spending balance -> fall back to onchain, no toast (or make it type .info instead)
• Lightning invoice only -> use title & description for toast: "Decoding Error" "This Lightning invoice has expired"

[jvsena42]

Draft to also cover #328 cases

[jvsena42]

@piotr-iohk we probably need a E2E update

[piotr-iohk]

@piotr-iohk we probably need a E2E update

Yes, it's already in place in corresponding e2e branch -> synonymdev/bitkit-e2e-tests#97