refactor(ui): remove pick-up-in-terminal, keep ConPTY as the single session entry

Two context-menu entries opened a Claude session for the same task via different
mechanisms (embedded ConPTY vs. an external wt terminal). Drop the external-terminal
path entirely, including its worker hub method, launcher plumbing, and localization
keys, since the embedded ConPTY session already covers every case it did.

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

@@ -6,7 +6,7 @@
              x:Class="ClaudeDo.Ui.Views.Islands.Detail.TaskHeaderBar"
              x:DataType="vm:DetailsIslandViewModel">
 
-  <Grid ColumnDefinitions="*,Auto,Auto,Auto">
+  <Grid ColumnDefinitions="*,Auto,Auto">
 
     <!-- Column 0: id badge + editable title -->
     <StackPanel Grid.Column="0" Spacing="0">
@@ -27,18 +27,8 @@
                Padding="0"/>
     </StackPanel>
 
-    <!-- Column 1: pick up in terminal (review / failed) -->
+    <!-- Column 1: trash button (not running) -->
     <Button Grid.Column="1" Classes="icon-btn"
-            Command="{Binding PickUpInTerminalCommand}"
-            ToolTip.Tip="{loc:Tr details.pickUpInTerminalTip}"
-            IsVisible="{Binding CanPickUpInTerminal}"
-            VerticalAlignment="Top"
-            Margin="6,0,0,0">
-      <PathIcon Data="{StaticResource Icon.ArrowOut}" Width="14" Height="14"/>
-    </Button>
-
-    <!-- Column 2: trash button (not running) -->
-    <Button Grid.Column="2" Classes="icon-btn"
             Command="{Binding DeleteTaskCommand}"
             ToolTip.Tip="{loc:Tr details.deleteTaskTip}"
             IsVisible="{Binding !IsRunning}"
@@ -48,8 +38,8 @@
                 Foreground="{DynamicResource BloodBrush}"/>
     </Button>
 
-    <!-- Column 2: skull button (running) -->
-    <Button Grid.Column="2" Classes="icon-btn"
+    <!-- Column 1: skull button (running) -->
+    <Button Grid.Column="1" Classes="icon-btn"
             Command="{Binding StopCommand}"
             ToolTip.Tip="{loc:Tr details.killSessionTip}"
             IsVisible="{Binding IsRunning}"
@@ -59,8 +49,8 @@
                 Foreground="{DynamicResource BloodBrush}"/>
     </Button>
 
-    <!-- Column 3: gear button with agent settings flyout -->
-    <Button Grid.Column="3" Classes="icon-btn"
+    <!-- Column 2: gear button with agent settings flyout -->
+    <Button Grid.Column="2" Classes="icon-btn"
             ToolTip.Tip="{loc:Tr details.agentSettingsTip}"
             IsEnabled="{Binding AgentSettings.IsEnabled}"
             VerticalAlignment="Top"

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

@@ -58,9 +58,6 @@
             <Separator/>
             <MenuItem Header="{loc:Tr tasks.ctxOpenConPtySession}"
                       Click="OnOpenConPtySessionClick"/>
-            <MenuItem Header="{loc:Tr tasks.ctxPickUpInTerminal}"
-                      Click="OnPickUpInTerminalClick"
-                      IsVisible="{Binding CanPickUpInTerminal}"/>
             <MenuItem Header="{loc:Tr tasks.ctxOpenPlanningSession}"
                       Click="OnOpenPlanningSessionClick"
                       IsVisible="{Binding CanOpenPlanningSession}"/>

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

@@ -82,12 +82,6 @@ public partial class TaskRowView : UserControl
             vm.OpenConPtySessionCommand.Execute(row);
     }
 
-    private async void OnPickUpInTerminalClick(object? sender, RoutedEventArgs e)
-    {
-        if (DataContext is TaskRowViewModel row && FindTasksVm() is { } vm)
-            await vm.PickUpInTerminalCommand.ExecuteAsync(row);
-    }
-
     private async void OnResumePlanningSessionClick(object? sender, RoutedEventArgs e)
     {
         if (DataContext is TaskRowViewModel row && FindTasksVm() is { } vm)