fix: AlertWindow's handleCancel

Signed-off-by: Arufonsu <17498701+Arufonsu@users.noreply.github.com>

Author: Arufonsu

Intersect.Client.Core/Interface/Shared/AlertWindow.cs

@@ -20,6 +20,7 @@ public record struct Alert(string Message, string? Title = default, AlertType Ty
 public class AlertWindow : InputBox
 {
     private static readonly HashSet<AlertWindow> _instances = [];
+    private readonly GwenEventHandler<EventArgs>? _handleCancel;
 
     private AlertWindow(
         string title,
@@ -39,6 +40,8 @@ private AlertWindow(
         userData: userData
     )
     {
+        _handleCancel = handleCancel;
+
         Icon = GameContentManager.Current.GetTexture(
             TextureType.Gui,
             $"icon.alert.{alertType.ToString().ToLowerInvariant()}.png"
@@ -49,6 +52,15 @@ private AlertWindow(
 
         var titleLabelMargin = TitleLabel.Margin;
         TitleLabel.Margin = titleLabelMargin with { Left = titleLabelMargin.Left + 4 };
+
+        // Subscribe to the Closed event to handle X button clicks
+        Closed += OnWindowClosed;
+    }
+
+    private void OnWindowClosed(Base sender, EventArgs args)
+    {
+        // Trigger the cancel handler when window is closed via X button
+        _handleCancel?.Invoke(this, args);
     }
 
     protected override void OnCanceled(Base sender, EventArgs args)