feat(wallet): surface immature balance separately from confirmed

Extract confirmation-threshold logic into UtxoSpendability (shared by
TransactionFactory and WalletSynchronizer) and use it to compute
ImmatureSats, so coinbase/under-confirmed amounts are shown separately
from spendable balance in the GUI and CLI instead of being lumped into
"confirmed".

src/App/Localization/Loc.cs

@@ -389,6 +389,7 @@ public sealed class Loc
         ["msg.height"]            = ["altezza",                                                           "height",                       "altura",                               "hauteur",                                  "altura",                                   "Höhe"],
         ["msg.pending"]           = ["in attesa di conferma",                                             "pending confirmation",         "pendiente de confirmación",            "en attente de confirmation",               "aguardando confirmação",                   "ausstehende Bestätigung"],
         ["msg.notspendable"]      = ["non ancora spendibile",                                             "not yet spendable",            "aún no gastable",                      "pas encore dépensable",                    "ainda não gastável",                       "noch nicht verwendbar"],
+        ["msg.immature"]          = ["in maturazione",                                                    "maturing",                      "en maduración",                        "en maturation",                            "em maturação",                             "in Reifung"],
         ["msg.settings.saved"]    = ["Impostazioni salvate.",                                             "Settings saved.",              "Configuración guardada.",              "Paramètres enregistrés.",                  "Configurações salvas.",                    "Einstellungen gespeichert."],
         ["msg.certreset"]         = [
             "Certificati SSL azzerati: riprova la connessione.",

src/App/ViewModels/MainWindowViewModel.Receive.cs

@@ -25,6 +25,9 @@ public partial class MainWindowViewModel
     [ObservableProperty]
     private string unconfirmedText = "";
 
+    [ObservableProperty]
+    private string immatureText = "";
+
     [ObservableProperty]
     private string networkInfo = "";
 
@@ -249,6 +252,7 @@ public partial class MainWindowViewModel
         {
             BalanceText = $"0.00000000 {Profile.CoinUnit}";
             UnconfirmedText = "";
+            ImmatureText = "";
             ReceiveAddress = _account.GetReceiveAddress(0).ToString();
             History.Clear();
             Addresses.Clear();
@@ -261,11 +265,14 @@ public partial class MainWindowViewModel
                     $"m/{_doc!.AccountPath}/0/{i}"));
             return;
         }
-        BalanceText = Fmt(cache.ConfirmedSats);
+        BalanceText = Fmt(cache.ConfirmedSats - cache.ImmatureSats);
         var pending = cache.History.Where(t => t.Height <= 0).Sum(t => t.DeltaSats);
         UnconfirmedText = pending != 0
             ? $"{Loc.Tr("msg.pending")}: {(pending > 0 ? "+" : "")}{Fmt(pending)} — {Loc.Tr("msg.notspendable")}"
             : "";
+        ImmatureText = cache.ImmatureSats != 0
+            ? $"{Loc.Tr("msg.immature")}: {Fmt(cache.ImmatureSats)} — {Loc.Tr("msg.notspendable")}"
+            : "";
         ReceiveAddress = _account.GetReceiveAddress(cache.NextReceiveIndex).ToString();
         History.Clear();
         foreach (var tx in cache.History)

src/App/ViewModels/MainWindowViewModel.Sync.cs

@@ -288,6 +288,7 @@ public partial class MainWindowViewModel
                     TipHeight = result.TipHeight,
                     ConfirmedSats = result.ConfirmedSats,
                     UnconfirmedSats = result.UnconfirmedSats,
+                    ImmatureSats = result.ImmatureSats,
                     NextReceiveIndex = result.NextReceiveIndex,
                     NextChangeIndex = result.NextChangeIndex,
                     History = [.. result.History],

src/App/Views/MainView.axaml

@@ -314,6 +314,9 @@
                     <TextBlock Text="{Binding UnconfirmedText}" Foreground="#FCD34D"
                                TextWrapping="Wrap"
                                IsVisible="{Binding UnconfirmedText, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+                    <TextBlock Text="{Binding ImmatureText}" Foreground="#FCD34D"
+                               TextWrapping="Wrap"
+                               IsVisible="{Binding ImmatureText, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
                     <TextBlock Text="{Binding NetworkInfo}" Classes="on-hero" FontSize="12"
                                Margin="0,2,0,0"/>
                 </StackPanel>