refactor(ui): drop duplicate converters and normalize binding in ListsIslandView

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ClaudeDo.Ui/Views/Islands/ListsIslandView.axaml

@@ -4,12 +4,6 @@
              xmlns:converters="using:ClaudeDo.Ui.Converters"
              x:Class="ClaudeDo.Ui.Views.Islands.ListsIslandView"
              x:DataType="vm:ListsIslandViewModel">
-  <UserControl.Resources>
-    <converters:UpperCaseConverter x:Key="UpperCase"/>
-    <converters:IconKeyConverter   x:Key="IconKey"/>
-    <converters:DotBrushConverter  x:Key="DotBrush"/>
-  </UserControl.Resources>
-
   <DockPanel LastChildFill="True">
 
     <!-- ── Header ── -->
@@ -86,10 +80,8 @@
                   <!-- Left accent bar for active state -->
                   <Border Grid.Column="0" Grid.ColumnSpan="3"
                           Background="Transparent"
-                          CornerRadius="8" IsHitTestVisible="False">
-                    <Border.IsVisible>
-                      <Binding Path="IsActive"/>
-                    </Border.IsVisible>
+                          CornerRadius="8" IsHitTestVisible="False"
+                          IsVisible="{Binding IsActive}">
                     <Border Width="2" Height="16"
                             Background="{DynamicResource AccentBrush}"
                             CornerRadius="1"