fix(mission-control): reset cursor to arrow over pane header buttons

Cursor inherits down the visual tree, so buttons in the draggable pane header kept the SizeAll cursor.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/ClaudeDo.Ui/Views/MissionControl/ConPtyPaneView.axaml

@@ -19,6 +19,12 @@
               Background="{DynamicResource Surface2Brush}"
               BorderBrush="{DynamicResource LineBrush}"
               BorderThickness="0,0,0,1" Padding="8,3">
+        <!-- Cursor inherits down the tree; without this the buttons keep the header's SizeAll. -->
+        <Border.Styles>
+          <Style Selector="Button">
+            <Setter Property="Cursor" Value="Arrow" />
+          </Style>
+        </Border.Styles>
         <Grid ColumnDefinitions="*,Auto,Auto,Auto">
           <TextBlock Grid.Column="0" Classes="meta" Text="{Binding DisplayTitle}"
                      TextTrimming="CharacterEllipsis"