feat(ui): polish worktrees overview modal

- Restyle to match ListSettingsModalView: custom title bar, DeepBrush
  toolbar, LineBrush footer, SurfaceBrush outer border, no system chrome
- Add column header row (TASK / BRANCH / STATE / DIFF / AGE) with
  TextFaintBrush + MonoFont + LetterSpacing, separator line below
- Replace wt-row style with task-row-equivalent: transparent bg,
  CornerRadius 8, 1px border, :pointerover + .selected transitions
- Add IsSelected to WorktreeOverviewRowViewModel; SelectRow() helper
  on modal VM clears previous selection before setting new one
- Wire OnRowTapped in code-behind for click-to-select
- Wire ShowDiff: VM takes Func<WorktreeModalViewModel> factory, builds
  diffVm and delegates window creation to both call sites (MainWindow
  and ListsIslandView); register Func<WorktreeModalViewModel> in DI

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ClaudeDo.App/Program.cs

@@ -95,6 +95,7 @@ sealed class Program
 
         // ViewModels
         sc.AddTransient<WorktreeModalViewModel>();
+        sc.AddTransient<Func<WorktreeModalViewModel>>(sp => () => sp.GetRequiredService<WorktreeModalViewModel>());
         sc.AddTransient<WorktreesOverviewModalViewModel>();
         sc.AddTransient<Func<WorktreesOverviewModalViewModel>>(sp => () => sp.GetRequiredService<WorktreesOverviewModalViewModel>());
         sc.AddSingleton<IPrimeScheduleApi, WorkerPrimeScheduleApi>();

src/ClaudeDo.Ui/ViewModels/Modals/WorktreesOverviewModalViewModel.cs

@@ -24,6 +24,7 @@ public sealed partial class WorktreeOverviewRowViewModel : ViewModelBase
     [ObservableProperty] private string? _diffStat;
     [ObservableProperty] private DateTime _createdAt;
     [ObservableProperty] private bool _pathExistsOnDisk;
+    [ObservableProperty] private bool _isSelected;
 
     public string AgeText => FormatAge(DateTime.UtcNow - CreatedAt);
     public bool IsActive => State == WorktreeState.Active;
@@ -48,24 +49,34 @@ public sealed partial class WorktreesGroupViewModel : ViewModelBase
 public sealed partial class WorktreesOverviewModalViewModel : ViewModelBase
 {
     private readonly WorkerClient _worker;
+    private readonly Func<WorktreeModalViewModel> _diffVmFactory;
 
     [ObservableProperty] private string? _listIdFilter;
     [ObservableProperty] private string _title = "Worktrees";
     [ObservableProperty] private bool _isGlobal;
     [ObservableProperty] private bool _isBusy;
     [ObservableProperty] private string? _statusMessage;
+    [ObservableProperty] private WorktreeOverviewRowViewModel? _selectedRow;
 
     public ObservableCollection<WorktreeOverviewRowViewModel> Rows { get; } = new();
     public ObservableCollection<WorktreesGroupViewModel> Groups { get; } = new();
 
     public Action? CloseAction { get; set; }
-    public Action<WorktreeOverviewRowViewModel>? ShowDiffAction { get; set; }
+    public Action<WorktreeModalViewModel>? ShowDiffAction { get; set; }
     public Action<string, string>? JumpToTaskAction { get; set; }
     public Func<string, Task<bool>>? ConfirmAction { get; set; }
 
-    public WorktreesOverviewModalViewModel(WorkerClient worker)
+    public WorktreesOverviewModalViewModel(WorkerClient worker, Func<WorktreeModalViewModel> diffVmFactory)
     {
         _worker = worker;
+        _diffVmFactory = diffVmFactory;
+    }
+
+    public void SelectRow(WorktreeOverviewRowViewModel row)
+    {
+        if (SelectedRow is not null) SelectedRow.IsSelected = false;
+        SelectedRow = row;
+        row.IsSelected = true;
     }
 
     public void Configure(string? listId, string? listName)
@@ -136,7 +147,9 @@ public sealed partial class WorktreesOverviewModalViewModel : ViewModelBase
     private void ShowDiff(WorktreeOverviewRowViewModel? row)
     {
         if (row is null) return;
-        ShowDiffAction?.Invoke(row);
+        var diffVm = _diffVmFactory();
+        diffVm.WorktreePath = row.Path;
+        ShowDiffAction?.Invoke(diffVm);
     }
 
     [RelayCommand]

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

@@ -38,7 +38,15 @@ public partial class ListsIslandView : UserControl
                             if (item is not null) v.SelectedList = item;
                         }
                     };
-                    // TODO: ShowDiffAction and ConfirmAction not wired in v1
+                    modal.ShowDiffAction = diffVm =>
+                    {
+                        var top2 = TopLevel.GetTopLevel(this) as Window;
+                        if (top2 is null) return;
+                        var dlg = new WorktreeModalView { DataContext = diffVm };
+                        diffVm.CloseAction = () => dlg.Close();
+                        _ = diffVm.LoadAsync();
+                        _ = dlg.ShowDialog(top2);
+                    };
                     var top = TopLevel.GetTopLevel(this) as Window;
                     if (top is null) window.Show();
                     else await window.ShowDialog(top);

src/ClaudeDo.Ui/Views/MainWindow.axaml.cs

@@ -3,6 +3,7 @@ using Avalonia.Controls;
 using Avalonia.Input;
 using ClaudeDo.Ui.ViewModels;
 using ClaudeDo.Ui.ViewModels.Islands;
+using ClaudeDo.Ui.ViewModels.Modals;
 using ClaudeDo.Ui.Views.Modals;
 using ClaudeDo.Ui.Views.Planning;
 
@@ -45,7 +46,13 @@ public partial class MainWindow : Window
                         if (item is not null && s.Lists is not null) s.Lists.SelectedList = item;
                     }
                 };
-                // TODO: ShowDiffAction and ConfirmAction not wired in v1
+                modal.ShowDiffAction = diffVm =>
+                {
+                    var diffDlg = new WorktreeModalView { DataContext = diffVm };
+                    diffVm.CloseAction = () => diffDlg.Close();
+                    _ = diffVm.LoadAsync();
+                    _ = diffDlg.ShowDialog(this);
+                };
                 await dlg.ShowDialog(this);
             };
         }

src/ClaudeDo.Ui/Views/Modals/WorktreesOverviewModalView.axaml

@@ -7,11 +7,16 @@
         Title="{Binding Title}"
         Width="900" Height="560" MinWidth="640" MinHeight="360"
         WindowStartupLocation="CenterOwner"
-        Background="{DynamicResource VoidBrush}">
+        Background="{DynamicResource VoidBrush}"
+        SystemDecorations="None"
+        ExtendClientAreaToDecorationsHint="True">
+
   <Window.Resources>
     <converters:WorktreeStateColorConverter x:Key="WorktreeStateColor"/>
     <DataTemplate x:Key="WorktreeRowTemplate" x:DataType="vm:WorktreeOverviewRowViewModel">
-      <Border Classes="wt-row">
+      <Border Classes="wt-row"
+              Classes.selected="{Binding IsSelected}"
+              Tapped="OnRowTapped">
         <Border.ContextMenu>
           <ContextMenu>
             <MenuItem Header="Show diff"
@@ -80,27 +85,95 @@
 
   <Window.Styles>
     <Style Selector="Border.wt-row">
-      <Setter Property="Background" Value="{DynamicResource DeepBrush}"/>
+      <Setter Property="Padding"         Value="12,10"/>
+      <Setter Property="CornerRadius"    Value="8"/>
+      <Setter Property="Background"      Value="Transparent"/>
       <Setter Property="BorderBrush"     Value="{DynamicResource LineBrush}"/>
-      <Setter Property="BorderThickness" Value="0,0,0,1"/>
-      <Setter Property="Padding" Value="10,8"/>
+      <Setter Property="BorderThickness" Value="1"/>
+      <Setter Property="Margin"          Value="0,0,0,6"/>
+      <Setter Property="Cursor"          Value="Hand"/>
+      <Setter Property="Transitions">
+        <Transitions>
+          <BrushTransition Property="BorderBrush" Duration="0:0:0.10"/>
+        </Transitions>
+      </Setter>
+    </Style>
+    <Style Selector="Border.wt-row:pointerover">
+      <Setter Property="BorderBrush" Value="{DynamicResource LineBrightBrush}"/>
+    </Style>
+    <Style Selector="Border.wt-row.selected">
+      <Setter Property="BorderBrush" Value="{DynamicResource LineBrightBrush}"/>
     </Style>
   </Window.Styles>
 
-  <DockPanel LastChildFill="True" Margin="12">
-    <StackPanel DockPanel.Dock="Top" Orientation="Horizontal" Spacing="8" Margin="0,0,0,8">
+  <Border Background="{DynamicResource SurfaceBrush}"
+          BorderBrush="{DynamicResource LineBrush}"
+          BorderThickness="1">
+    <Grid RowDefinitions="36,Auto,*,52">
+
+      <!-- Title bar -->
+      <Border Grid.Row="0"
+              Background="{DynamicResource DeepBrush}"
+              BorderBrush="{DynamicResource LineBrush}"
+              BorderThickness="0,0,0,1"
+              PointerPressed="OnTitleBarPressed">
+        <Grid ColumnDefinitions="*,Auto">
+          <TextBlock Grid.Column="0"
+                     Text="{Binding Title}"
+                     VerticalAlignment="Center"
+                     Margin="14,0,0,0"
+                     FontSize="12"
+                     FontWeight="SemiBold"
+                     Foreground="{DynamicResource TextBrush}"/>
+          <Button Grid.Column="1"
+                  Content="✕"
+                  Command="{Binding CloseCommand}"
+                  Margin="0,0,8,0"
+                  Width="28" Height="28"
+                  FontSize="11"
+                  HorizontalContentAlignment="Center"
+                  VerticalContentAlignment="Center"/>
+        </Grid>
+      </Border>
+
+      <!-- Toolbar -->
+      <Border Grid.Row="1"
+              Background="{DynamicResource DeepBrush}"
+              BorderBrush="{DynamicResource LineBrush}"
+              BorderThickness="0,0,0,1"
+              Padding="12,8">
+        <StackPanel Orientation="Horizontal" Spacing="8">
           <Button Content="Refresh" Command="{Binding RefreshCommand}" IsEnabled="{Binding !IsBusy}"/>
           <Button Content="Cleanup finished" Command="{Binding CleanupFinishedCommand}" IsEnabled="{Binding !IsBusy}"/>
           <TextBlock Text="{Binding StatusMessage}" VerticalAlignment="Center" Margin="12,0,0,0"
                      Foreground="{DynamicResource TextDimBrush}"/>
         </StackPanel>
+      </Border>
 
-    <StackPanel DockPanel.Dock="Bottom" Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,8,0,0">
-      <Button Content="Close" Command="{Binding CloseCommand}"/>
-    </StackPanel>
+      <!-- Content -->
+      <ScrollViewer Grid.Row="2" Padding="12,8">
+        <StackPanel>
+          <!-- Column headers -->
+          <Grid ColumnDefinitions="*,200,90,80,80" Margin="12,0,12,4">
+            <TextBlock Grid.Column="0" Text="TASK"
+                       FontFamily="{DynamicResource MonoFont}" FontSize="10" LetterSpacing="1.4"
+                       Foreground="{DynamicResource TextFaintBrush}"/>
+            <TextBlock Grid.Column="1" Text="BRANCH"
+                       FontFamily="{DynamicResource MonoFont}" FontSize="10" LetterSpacing="1.4"
+                       Foreground="{DynamicResource TextFaintBrush}"/>
+            <TextBlock Grid.Column="2" Text="STATE"
+                       FontFamily="{DynamicResource MonoFont}" FontSize="10" LetterSpacing="1.4"
+                       Foreground="{DynamicResource TextFaintBrush}"/>
+            <TextBlock Grid.Column="3" Text="DIFF"
+                       FontFamily="{DynamicResource MonoFont}" FontSize="10" LetterSpacing="1.4"
+                       Foreground="{DynamicResource TextFaintBrush}"/>
+            <TextBlock Grid.Column="4" Text="AGE"
+                       FontFamily="{DynamicResource MonoFont}" FontSize="10" LetterSpacing="1.4"
+                       Foreground="{DynamicResource TextFaintBrush}"/>
+          </Grid>
+          <Border Height="1" Background="{DynamicResource LineBrush}" Margin="0,0,0,8"/>
 
-    <ScrollViewer>
-      <Grid>
+          <!-- Rows (per-list) -->
           <ItemsControl ItemsSource="{Binding Rows}" IsVisible="{Binding !IsGlobal}">
             <ItemsControl.ItemTemplate>
               <DataTemplate DataType="vm:WorktreeOverviewRowViewModel">
@@ -109,6 +182,7 @@
             </ItemsControl.ItemTemplate>
           </ItemsControl>
 
+          <!-- Rows (global, grouped) -->
           <ItemsControl ItemsSource="{Binding Groups}" IsVisible="{Binding IsGlobal}">
             <ItemsControl.ItemTemplate>
               <DataTemplate DataType="vm:WorktreesGroupViewModel">
@@ -124,7 +198,20 @@
               </DataTemplate>
             </ItemsControl.ItemTemplate>
           </ItemsControl>
-      </Grid>
+        </StackPanel>
       </ScrollViewer>
-  </DockPanel>
+
+      <!-- Footer -->
+      <Border Grid.Row="3"
+              Background="{DynamicResource DeepBrush}"
+              BorderBrush="{DynamicResource LineBrush}"
+              BorderThickness="0,1,0,0"
+              Padding="12,10">
+        <StackPanel Orientation="Horizontal" HorizontalAlignment="Right">
+          <Button Content="Close" Command="{Binding CloseCommand}"/>
+        </StackPanel>
+      </Border>
+
+    </Grid>
+  </Border>
 </Window>

src/ClaudeDo.Ui/Views/Modals/WorktreesOverviewModalView.axaml.cs

@@ -1,8 +1,25 @@
 using Avalonia.Controls;
+using Avalonia.Input;
+using ClaudeDo.Ui.ViewModels.Modals;
 
 namespace ClaudeDo.Ui.Views.Modals;
 
 public partial class WorktreesOverviewModalView : Window
 {
     public WorktreesOverviewModalView() => InitializeComponent();
+
+    private void OnRowTapped(object? sender, TappedEventArgs e)
+    {
+        if (sender is Border { DataContext: WorktreeOverviewRowViewModel row } &&
+            DataContext is WorktreesOverviewModalViewModel vm)
+        {
+            vm.SelectRow(row);
+        }
+    }
+
+    private void OnTitleBarPressed(object? sender, PointerPressedEventArgs e)
+    {
+        if (e.GetCurrentPoint(this).Properties.IsLeftButtonPressed)
+            BeginMoveDrag(e);
+    }
 }