Desktop: decide a titlebar double-click on the press, before the drag can swallow it

src/DodoSSH.Client.App/Views/SettingsTitleBar.axaml.cs

@@ -9,6 +9,8 @@ internal sealed partial class SettingsTitleBar : UserControl
 {
     public SettingsTitleBar() => InitializeComponent();
 
+    private readonly CaptionPresses presses = new();
+
     private Window? Host => TopLevel.GetTopLevel(this) as Window;
 
     /// <summary>Left button only, and only on a press nothing inside the bar has already handled.</summary>
@@ -19,6 +21,15 @@ internal sealed partial class SettingsTitleBar : UserControl
             return;
         }
 
+        // Decided on the press, before the drag would take it: see CaptionPresses.
+        if (presses.IsSecond(e, this))
+        {
+            OnToggleMaximised(sender, e);
+            e.Handled = true;
+
+            return;
+        }
+
         Host?.BeginMoveDrag(e);
     }
 
@@ -31,6 +42,7 @@ internal sealed partial class SettingsTitleBar : UserControl
     }
 
     /// <summary>Both the button and a double-click on the bar arrive here, as Windows convention expects.</summary>
+    /// <remarks>The double-click by way of <see cref="OnDrag"/>; see <see cref="CaptionPresses"/>.</remarks>
     private void OnToggleMaximised(object? sender, RoutedEventArgs e)
     {
         if (Host is not { } window)