fix: wallet screen showing "No wallet connected" on first open

The WalletViewModel.init() was called inside LaunchedEffect (async),
but hasWalletSetup() was checked synchronously during the first
composition frame—before init had run. Moved init to run synchronously
during composition and made hasWalletSetup a reactive StateFlow so the
UI updates when wallet state changes.

https://claude.ai/code/session_01JFogiwyR4CPVP8cRznqahJ

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

@@ -73,10 +73,9 @@ fun WalletScreen(
     nav: INav,
 ) {
     val walletViewModel: WalletViewModel = viewModel()
+    walletViewModel.init(accountViewModel.account)
 
-    LaunchedEffect(accountViewModel) {
-        walletViewModel.init(accountViewModel.account)
-    }
+    val hasWallet by walletViewModel.hasWalletSetup.collectAsState()
 
     Scaffold(
         topBar = {
@@ -93,7 +92,7 @@ fun WalletScreen(
             )
         },
     ) { padding ->
-        if (!walletViewModel.hasWalletSetup()) {
+        if (!hasWallet) {
             NoWalletSetup(
                 modifier = Modifier.padding(padding),
                 nav = nav,

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

@@ -73,6 +73,9 @@ sealed class ReceiveState {
 class WalletViewModel : ViewModel() {
     private var account: Account? = null
 
+    private val _hasWalletSetup = MutableStateFlow(false)
+    val hasWalletSetup = _hasWalletSetup.asStateFlow()
+
     private val _balanceSats = MutableStateFlow<Long?>(null)
     val balanceSats = _balanceSats.asStateFlow()
 
@@ -96,9 +99,12 @@ class WalletViewModel : ViewModel() {
 
     fun init(account: Account) {
         this.account = account
+        _hasWalletSetup.value = account.nip47SignerState?.hasWalletConnectSetup() == true
     }
 
-    fun hasWalletSetup(): Boolean = account?.nip47SignerState?.hasWalletConnectSetup() == true
+    fun refreshWalletSetup() {
+        _hasWalletSetup.value = account?.nip47SignerState?.hasWalletConnectSetup() == true
+    }
 
     fun fetchBalance() {
         val acc = account ?: return