feat: implement command, fix icon foreground in light mode.

src/Ursa.Themes.Semi/Controls/Breadcrumb.axaml

@@ -33,7 +33,7 @@
                             VerticalAlignment="Center"
                             Content="{TemplateBinding Icon}"
                             ContentTemplate="{TemplateBinding IconTemplate}"
-                            Foreground="{TemplateBinding Foreground}"
+                            Foreground="{DynamicResource SemiColorText2}"
                             IsVisible="{TemplateBinding Icon,
                                                         Converter={x:Static ObjectConverters.IsNotNull}}" />
                         <ContentPresenter

src/Ursa/Controls/Breadcrumb/BreadcrumbItem.cs

@@ -3,6 +3,7 @@ using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Templates;
+using Avalonia.Input;
 
 namespace Ursa.Controls;
 
@@ -47,8 +48,9 @@ public class BreadcrumbItem: ContentControl
         set => SetValue(IconTemplateProperty, value);
     }
 
-    static BreadcrumbItem()
+    protected override void OnPointerPressed(PointerPressedEventArgs e)
     {
-        
+        base.OnPointerPressed(e);
+        Command?.Execute(null);
     }
 }