fix(ui): filled window icons, boxed task rows, proper explorer button

- Window controls (min/close) were stroke-only paths — PathIcon fills
  geometries, so only max rendered. Swap all three (and BrandCheck) to
  closed filled shapes.
- Task rows now have a 1px LineBrush border + rounded 8px box with
  subtle AccentSoft hover, matching the mock's visible row separation.
- "Open in explorer" button switched from icon-btn to btn class so it
  matches "Open diff" / "Worktree" framing, with a proper Lucide-style
  filled arrow geometry.

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

src/ClaudeDo.Ui/Design/IslandStyles.axaml

@@ -18,12 +18,12 @@
   <!-- ICON GEOMETRY RESOURCES                                      -->
   <!-- ============================================================ -->
   <Styles.Resources>
-    <!-- Window control icons (from icons.jsx: min, max, close) -->
+    <!-- Window control icons — filled geometries (PathIcon fills, not strokes) -->
-    <StreamGeometry x:Key="Icon.WinMin">M5 10h10</StreamGeometry>
+    <StreamGeometry x:Key="Icon.WinMin">M4 9 H16 V11 H4 Z</StreamGeometry>
-    <StreamGeometry x:Key="Icon.WinMax">M5 5 h10 v10 h-10 z</StreamGeometry>
+    <StreamGeometry x:Key="Icon.WinMax">M4 4 H16 V6 H4 Z M4 14 H16 V16 H4 Z M4 4 H6 V16 H4 Z M14 4 H16 V16 H14 Z</StreamGeometry>
-    <StreamGeometry x:Key="Icon.WinClose">M5 5l14 14M19 5L5 19</StreamGeometry>
+    <StreamGeometry x:Key="Icon.WinClose">M4 5 L5 4 L16 15 L15 16 Z M15 4 L16 5 L5 16 L4 15 Z</StreamGeometry>
-    <!-- Brand check glyph (checkbox-style tick inside a rounded square) -->
+    <!-- Brand check glyph — filled rounded square with inset tick -->
-    <StreamGeometry x:Key="Icon.BrandCheck">M3 3 h18 v18 h-18 z M6 12 l4 4 8-8</StreamGeometry>
+    <StreamGeometry x:Key="Icon.BrandCheck">M3 3 H21 V21 H3 Z M6 12 L7 11 L10 14 L17 7 L18 8 L10 16 Z</StreamGeometry>
 
     <!-- ============================================================ -->
     <!-- Icons — central icon library (Phase B)                      -->
@@ -78,6 +78,9 @@
     <!-- Icon.Check -->
     <StreamGeometry x:Key="Icon.Check">M4 12l5 5 11-11</StreamGeometry>
 
+    <!-- Icon.ArrowOut — filled arrow for "open external" button -->
+    <StreamGeometry x:Key="Icon.ArrowOut">M13 4 H20 V11 H18 V7.4 L11.4 14 L10 12.6 L16.6 6 H13 Z M4 6 H10 V8 H6 V18 H16 V14 H18 V20 H4 Z</StreamGeometry>
+
   </Styles.Resources>
 
   <!-- ============================================================ -->
@@ -249,21 +252,25 @@
     <Setter Property="Padding"      Value="12,10" />
     <Setter Property="CornerRadius" Value="8" />
     <Setter Property="Background"   Value="Transparent" />
+    <Setter Property="BorderBrush"  Value="{StaticResource LineBrush}" />
+    <Setter Property="BorderThickness" Value="1" />
+    <Setter Property="Margin"       Value="0,0,0,6" />
     <Setter Property="Cursor"       Value="Hand" />
     <Setter Property="Transitions">
       <Transitions>
         <BrushTransition Property="Background" Duration="0:0:0.10"/>
+        <BrushTransition Property="BorderBrush" Duration="0:0:0.10"/>
       </Transitions>
     </Setter>
   </Style>
   <Style Selector="Border.task-row:pointerover">
-    <Setter Property="Background" Value="{StaticResource Surface2Brush}" />
+    <Setter Property="Background"  Value="{StaticResource AccentSoftBrush}" />
+    <Setter Property="BorderBrush" Value="{StaticResource LineBrightBrush}" />
   </Style>
   <Style Selector="Border.task-row.selected">
     <Setter Property="Background"      Value="{StaticResource Surface3Brush}" />
     <Setter Property="BorderBrush"     Value="{StaticResource AccentBrush}" />
-    <Setter Property="BorderThickness" Value="0,0,0,0" />
+    <Setter Property="BorderThickness" Value="1" />
-    <!-- Left-edge accent bar: use a nested Border child with Width=2 instead of inset shadow -->
   </Style>
 
   <!-- Checkbox indicator (the 18px circle that replaces the native CheckBox template) -->

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

@@ -124,9 +124,12 @@
       <StackPanel Orientation="Horizontal" Spacing="6" Margin="0,4,0,0">
         <Button Classes="btn" Content="Open diff" Command="{Binding OpenDiffCommand}"/>
         <Button Classes="btn" Content="Worktree" Command="{Binding OpenWorktreeCommand}"/>
-        <Button Classes="icon-btn" ToolTip.Tip="Open in file explorer"
+        <Button Classes="btn" ToolTip.Tip="Open in file explorer"
-                Command="{Binding OpenInExplorerCommand}">
+                Command="{Binding OpenInExplorerCommand}"
-          <TextBlock Text="→" FontFamily="{DynamicResource MonoFont}" FontSize="13"/>
+                Padding="8,6">
+          <PathIcon Data="{StaticResource Icon.ArrowOut}"
+                    Width="12" Height="12"
+                    Foreground="{DynamicResource TextDimBrush}"/>
         </Button>
       </StackPanel>