feat(lists): assign a colour to a sidebar folder

Tints the folder name and its guide line; picked from a swatch row in the folder settings.

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

@@ -153,7 +153,8 @@
               <TextBlock Grid.Column="2" Classes="list-label"
                          Text="{Binding Name}" ToolTip.Tip="{Binding Name}"
                          VerticalAlignment="Center" Margin="8,0" FontWeight="SemiBold"
-                         Foreground="{DynamicResource TextDimBrush}" FontSize="{StaticResource FontSizeBody}"/>
+                         Foreground="{Binding Color, Converter={x:Static converters:HexBrushConverter.Instance}, ConverterParameter=TextDimBrush}"
+                         FontSize="{StaticResource FontSizeBody}"/>
               <TextBlock Grid.Column="3" Classes="list-count"
                          Text="{Binding Count}" IsVisible="{Binding ShowCount}"/>
             </Grid>
@@ -163,7 +164,8 @@
                glyph); children start past it so their highlight never touches the line. -->
           <Panel IsVisible="{Binding !IsCollapsed}">
             <Border Width="1" HorizontalAlignment="Left" Margin="8,0,0,4"
-                    Background="{DynamicResource LineBrush}" IsHitTestVisible="False"/>
+                    Background="{Binding Color, Converter={x:Static converters:HexBrushConverter.Instance}, ConverterParameter=LineBrush}"
+                    IsHitTestVisible="False"/>
             <ItemsControl ItemsSource="{Binding Children}" Margin="14,0,0,0"/>
           </Panel>
         </StackPanel>