fix: consolidate wallet setup saves into a single signer call

All three saves (zap settings, lightning address, payment targets) now
run sequentially inside one accountViewModel.launchSigner block,
so the signer is only invoked once per save instead of three times.

- Extract sendPostSuspend() from UpdateZapAmountViewModel.sendPost()
- Extract saveLnAddressSuspend() from WalletViewModel.saveLnAddress()
- Extract savePaymentTargetsSuspend() from PaymentTargetsViewModel.savePaymentTargets()
- NIP47SetupScreen.onPost calls all three suspend fns in one launchSigner

https://claude.ai/code/session_017NPhwCnSzCuMn9sTX3ca37

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/actions/paymentTargets/PaymentTargetsViewModel.kt

@@ -79,9 +79,15 @@ class PaymentTargetsViewModel : ViewModel() {
     fun savePaymentTargets() {
         if (isModified) {
             accountViewModel.launchSigner {
-                account.savePaymentTargets(_paymentTargets.value)
-                refresh()
+                savePaymentTargetsSuspend()
             }
         }
     }
+
+    suspend fun savePaymentTargetsSuspend() {
+        if (isModified) {
+            account.savePaymentTargets(_paymentTargets.value)
+            refresh()
+        }
+    }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/UpdateZapAmountViewModel.kt

@@ -84,6 +84,12 @@ class UpdateZapAmountViewModel : ViewModel() {
     }
 
     fun sendPost() {
+        accountViewModel.launchSigner {
+            sendPostSuspend()
+        }
+    }
+
+    suspend fun sendPostSuspend() {
         val nip47Update =
             if (walletConnectRelay.text.isNotBlank() && walletConnectPubkey.text.isNotBlank()) {
                 val pubkeyHex =
@@ -110,7 +116,7 @@ class UpdateZapAmountViewModel : ViewModel() {
                 null
             }
 
-        accountViewModel.updateZapAmounts(amountSet, selectedZapType, nip47Update)
+        accountViewModel.account.updateZapAmounts(amountSet, selectedZapType, nip47Update)
 
         nextAmount = TextFieldValue("")
     }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/settings/NIP47SetupScreen.kt

@@ -105,9 +105,11 @@ fun NIP47SetupScreen(
                     nav.popBack()
                 },
                 onPost = {
-                    postViewModel.sendPost()
-                    walletViewModel.saveLnAddress()
-                    paymentTargetsViewModel.savePaymentTargets()
+                    accountViewModel.launchSigner {
+                        postViewModel.sendPostSuspend()
+                        walletViewModel.saveLnAddressSuspend()
+                        paymentTargetsViewModel.savePaymentTargetsSuspend()
+                    }
                     nav.popBack()
                 },
             )

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/wallet/WalletViewModel.kt

@@ -171,13 +171,17 @@ class WalletViewModel : ViewModel() {
 
     fun saveLnAddress() {
         val accountVm = accountViewModel ?: return
-        val acc = account ?: return
         accountVm.launchSigner {
-            val event = acc.userMetadata.sendNewUserMetadata(lnAddress = _lnAddress.value)
-            acc.sendLiterallyEverywhere(event)
+            saveLnAddressSuspend()
         }
     }
 
+    suspend fun saveLnAddressSuspend() {
+        val acc = account ?: return
+        val event = acc.userMetadata.sendNewUserMetadata(lnAddress = _lnAddress.value)
+        acc.sendLiterallyEverywhere(event)
+    }
+
     fun fetchBalance() {
         val acc = account ?: return
         viewModelScope.launch(Dispatchers.IO) {