feat(ui): resize detail split by dragging the console's top edge

Replace the standalone GridSplitter bar between the details card and the work
console with a transparent splitter over the gap above the console, so the user
drags the console's top edge to resize. Restore the prep-log terminal's inset
now that SessionTerminalView no longer hard-codes its own margin.

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

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

@@ -41,17 +41,19 @@
       <!-- Task detail: description/steps card (upper) + pinned work console (lower) -->
       <Grid IsVisible="{Binding IsTaskDetailVisible}"
             Margin="14,12,14,12"
-            RowDefinitions="2*,Auto,*">
+            RowDefinitions="2*,*">
         <ScrollViewer Grid.Row="0" VerticalScrollBarVisibility="Auto">
           <detail:DescriptionStepsCard VerticalAlignment="Top"/>
         </ScrollViewer>
+        <detail:WorkConsole Grid.Row="1" Margin="0,10,0,0"/>
+        <!-- Resize by dragging the console's top edge — a transparent splitter
+             over the gap above the console; no standalone separator bar. -->
         <GridSplitter Grid.Row="1"
-                      Height="4"
-                      Margin="0,8"
+                      VerticalAlignment="Top"
+                      Height="10"
                       HorizontalAlignment="Stretch"
                       ResizeDirection="Rows"
-                      Background="{DynamicResource LineBrush}"/>
-        <detail:WorkConsole Grid.Row="2"/>
+                      Background="Transparent"/>
       </Grid>
 
       <!-- Notes mode -->
@@ -70,6 +72,7 @@
           </Border>
           <Panel>
             <islands:SessionTerminalView
+                Margin="18,8,18,0"
                 Entries="{Binding PrepLog}" Label="daily-prep"
                 IsRunning="{Binding IsPrepRunning}"/>
             <TextBlock IsVisible="{Binding ShowPrepEmptyState}"