Add configurable thread item sorting

Wino.Mail.WinUI/Services/PreferencesService.cs

@@ -117,6 +117,12 @@ public class PreferencesService(IConfigurationService configurationService) : Ob
         set => SetPropertyAndSave(nameof(IsThreadingEnabled), value);
     }
 
+    public bool IsNewestThreadMailFirst
+    {
+        get => _configurationService.Get(nameof(IsNewestThreadMailFirst), true);
+        set => SetPropertyAndSave(nameof(IsNewestThreadMailFirst), value);
+    }
+
     public bool IsMailListActionBarEnabled
     {
         get => _configurationService.Get(nameof(IsMailListActionBarEnabled), false);

Wino.Mail.WinUI/Views/Mail/MailListPage.xaml.cs

@@ -990,10 +990,10 @@ public sealed partial class MailListPage : MailListPageAbstract,
                 }
                 else
                 {
-                    var firstChild = clickedThread.ThreadEmails.FirstOrDefault();
-                    if (firstChild != null)
+                    var defaultSelectedChild = clickedThread.GetDefaultSelectedThreadEmail();
+                    if (defaultSelectedChild != null)
                     {
-                        firstChild.IsSelected = true;
+                        defaultSelectedChild.IsSelected = true;
                     }
                 }