feat: update default model to qwen/qwen3.5-397b-a17b

SetupTui.cs

@@ -29,12 +29,36 @@ internal static class SetupTui
 
         // ── Model ─────────────────────────────────────────────────────
         AnsiConsole.MarkupLine($"  Current model: [cyan]{Markup.Escape(config.Model)}[/]");
-        string newModel = AnsiConsole.Prompt(
-            new TextPrompt<string>("  New model [dim](Enter to keep)[/]:")
-                .AllowEmpty());
 
-        if (!string.IsNullOrWhiteSpace(newModel))
-            config.Model = newModel.Trim();
+        var models = new List<(string Value, string Description)>
+        {
+            ("qwen/qwen3.5-397b-a17b", "smart, expensive"),
+            ("qwen/qwen3.5-35b-a3b", "cheapest"),
+            ("qwen/qwen3.5-27b", "fast"),
+            ("qwen/qwen3.5-122b-a10b", "smart"),
+            ("Custom...", "")
+        };
+
+        string selectedModel = AnsiConsole.Prompt(
+            new SelectionPrompt<(string Value, string Description)>()
+                .Title("  Select a model:")
+                .UseConverter(m => m.Value + (string.IsNullOrEmpty(m.Description) ? "" : $" [dim]({m.Description})[/]"))
+                .AddChoices(models))
+                .Value;
+
+        if (selectedModel == "Custom...")
+        {
+            string customModel = AnsiConsole.Prompt(
+                new TextPrompt<string>("  Enter custom model name:")
+                    .AllowEmpty());
+
+            if (!string.IsNullOrWhiteSpace(customModel))
+                config.Model = customModel.Trim();
+        }
+        else
+        {
+            config.Model = selectedModel;
+        }
 
         // ── Save ──────────────────────────────────────────────────────
         AnsiConsole.WriteLine();