feat(ui): wire redesigned detail island (header + description/steps card + work console)

Replace the long scrolling DetailsIslandView with the new pinned layout: a
separated TaskHeaderBar (trash↔skull, gear), a DescriptionStepsCard (text⇄steps
toggle, Preview = composed prompt), and a pinned WorkConsole (Output/Actions/
Session tabs). The three components now bind to DetailsIslandViewModel; their
scaffolding sample VMs are removed. Drops the old inline sections + AgentStripView.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/ClaudeDo.Ui/Views/Islands/Detail/WorkConsole.axaml

@@ -1,15 +1,11 @@
 <UserControl xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-             xmlns:vm="using:ClaudeDo.Ui.ViewModels.Islands.Detail"
+             xmlns:vm="using:ClaudeDo.Ui.ViewModels.Islands"
              xmlns:islands="using:ClaudeDo.Ui.Views.Islands"
              xmlns:loc="using:ClaudeDo.Ui.Localization"
-             x:DataType="vm:WorkConsoleViewModel"
+             x:DataType="vm:DetailsIslandViewModel"
              x:Class="ClaudeDo.Ui.Views.Islands.Detail.WorkConsole">
 
-  <Design.DataContext>
-    <vm:WorkConsoleViewModel />
-  </Design.DataContext>
-
   <UserControl.Styles>
     <Style Selector="Button.tab-btn">
       <Setter Property="Background"      Value="Transparent" />
@@ -223,7 +219,7 @@
               <TextBlock Classes="section-label" Text="OUTCOMES" Margin="0,0,0,2" />
               <ItemsControl ItemsSource="{Binding ChildOutcomes}">
                 <ItemsControl.ItemTemplate>
-                  <DataTemplate x:DataType="vm:WorkConsoleChildOutcomeRowViewModel">
+                  <DataTemplate x:DataType="vm:ChildOutcomeRowViewModel">
                     <Grid ColumnDefinitions="*,Auto,Auto" Margin="0,2">
                       <TextBlock Grid.Column="0" Text="{Binding Title}"
                                  TextTrimming="CharacterEllipsis"