diff --git a/.gitignore b/.gitignore
index cd42ee3..9ba2259 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 bin/
 obj/
+dist/
diff --git a/Core/Engine.cs b/Core/Engine.cs
index 50c7f8e..3a4d3af 100644
--- a/Core/Engine.cs
+++ b/Core/Engine.cs
@@ -19,6 +19,9 @@ abstract class Engine
     public abstract string Executable { get; }
     public abstract ModelOption[] Models { get; }
     public abstract string[] Efforts { get; }
+    /// <summary>Modello scelto all'avvio e a ogni cambio di CLI: il più piccolo, per risposte rapide ed economiche.</summary>
+    public abstract string DefaultModelId { get; }
+    public string DefaultEffort => "low";
     /// <summary>True se l'id di sessione lo genera il motore e l'app lo legge dall'output.</summary>
     public abstract bool OwnsSessionId { get; }
 
@@ -51,6 +54,7 @@ sealed class ClaudeEngine : Engine
     ];
 
     public override string[] Efforts { get; } = ["low", "medium", "high", "xhigh", "max"];
+    public override string DefaultModelId => "claude-haiku-5-5";
 
     public override List<string> BuildArgs(string prompt, string? sessionId, bool resume, string model, string effort, bool structured)
     {
@@ -86,6 +90,7 @@ sealed class CodexEngine : Engine
     ];
 
     public override string[] Efforts { get; } = ["low", "medium", "high", "xhigh", "max"];
+    public override string DefaultModelId => "gpt-5.6-luna";
 
     public override List<string> BuildArgs(string prompt, string? sessionId, bool resume, string model, string effort, bool structured)
     {
diff --git a/Gui/MainViewModel.cs b/Gui/MainViewModel.cs
index 747f612..96ce6d2 100644
--- a/Gui/MainViewModel.cs
+++ b/Gui/MainViewModel.cs
@@ -63,7 +63,7 @@ class MainViewModel : ObservableObject
 {
     static readonly ModelOption Default = new("Predefinito", "");
     static readonly ModelOption Custom = new("Altro ID…", "__custom");
-    const string DefaultEffort = "Predefinito";
+    const string NoEffort = "Predefinito";
 
     public ObservableCollection<MessageVm> Messages { get; } = [];
     public ObservableCollection<ChatItem> Chats { get; } = [];
@@ -102,7 +102,7 @@ class MainViewModel : ObservableObject
     bool busy, updating, sidebarOpen = true;
     ModelOption selectedModel = Default;
     string customModel = "";
-    string selectedEffort = DefaultEffort;
+    string selectedEffort = NoEffort;
     readonly RelayCommand<object> send, newChat;
 
     public MainViewModel()
@@ -188,8 +188,10 @@ class MainViewModel : ObservableObject
     {
         selectedEngine = choice;
         ModelChoices = [Default, .. choice.Engine.Models, Custom];
-        EffortChoices = [DefaultEffort, .. choice.Engine.Efforts];
-        SelectedModel = Default; CustomModel = ""; SelectedEffort = DefaultEffort;
+        EffortChoices = [NoEffort, .. choice.Engine.Efforts];
+        // valori iniziali: il modello più piccolo del motore ed effort basso ("Predefinito" resta selezionabile)
+        SelectedModel = ModelChoices.FirstOrDefault(m => m.Id == choice.Engine.DefaultModelId) ?? Default;
+        CustomModel = ""; SelectedEffort = choice.Engine.DefaultEffort;
         Raise(nameof(SelectedEngine)); Raise(nameof(Author)); Raise(nameof(InputPlaceholder)); Raise(nameof(BusyText));
     }
 
@@ -242,7 +244,7 @@ class MainViewModel : ObservableObject
         if (!CanSend) return;
         var text = input.Trim();
         var model = IsCustomModel ? customModel.Trim() : selectedModel.Id;
-        var effort = selectedEffort == DefaultEffort ? "" : selectedEffort;
+        var effort = selectedEffort == NoEffort ? "" : selectedEffort;
 
         Input = ""; IsBusy = true;
         Add("user", text);
diff --git a/scripts/publish.sh b/scripts/publish.sh
new file mode 100755
index 0000000..70e627a
--- /dev/null
+++ b/scripts/publish.sh
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+# Crea gli eseguibili single-file self-contained in dist/<rid>/.
+# Senza argomenti: win-x64 e linux-x64. Con argomenti: i rid indicati (es. linux-arm64).
+# Funziona da Linux, WSL e macOS (la compilazione per un altro sistema non richiede quel sistema).
+set -euo pipefail
+cd "$(dirname "$0")/.."
+
+rids=("$@")
+[ ${#rids[@]} -eq 0 ] && rids=(win-x64 linux-x64)
+
+for rid in "${rids[@]}"; do
+    echo "== $rid"
+    dotnet publish agent-wiki-ui.csproj -c Release -r "$rid" --self-contained -p:PublishSingleFile=true -o "dist/$rid" --nologo -v quiet
+    find "dist/$rid" -name '*.pdb' -delete # simboli delle librerie native: inutili a chi usa l'app
+done
+
+echo
+echo "Eseguibili pronti:"
+for rid in "${rids[@]}"; do ls -lh "dist/$rid" | awk -v r="$rid" 'NR>1 {print "  dist/" r "/" $9 "  (" $5 ")"}'; done