style<*>: remove unused brushes

src/Resources/Themes/Dark.xaml

@@ -9,8 +9,6 @@
     <SolidColorBrush x:Key="Brush.Popup" Color="#FF2B2B2B"/>
     <SolidColorBrush x:Key="Brush.Contents" Color="#FF1B1B1B"/>
     <SolidColorBrush x:Key="Brush.Badge" Color="#FF8F8F8F"/>
-    <SolidColorBrush x:Key="Brush.CommitViewer" Color="#FF222222"/>
-    <SolidColorBrush x:Key="Brush.SideBar" Color="#FF252525"/>
     <SolidColorBrush x:Key="Brush.Decorator" Color="#FF505050"/>
     <SolidColorBrush x:Key="Brush.Conflict" Color="#FFFAFAD2"/>
 
@@ -18,7 +16,6 @@
     <SolidColorBrush x:Key="Brush.Border1" Color="#FF7C7C7C"/>
     <SolidColorBrush x:Key="Brush.Border2" Color="#FF404040"/>
     <SolidColorBrush x:Key="Brush.Border3" Color="#FF252525"/>
-    <SolidColorBrush x:Key="Brush.Border4" Color="#FF252525"/>
     
     <SolidColorBrush x:Key="Brush.FG1" Color="#FFF1F1F1"/>
     <SolidColorBrush x:Key="Brush.FG2" Color="#40F1F1F1"/>

src/Resources/Themes/Light.xaml

@@ -9,8 +9,6 @@
     <SolidColorBrush x:Key="Brush.Popup" Color="#FFF8F8F8"/>
     <SolidColorBrush x:Key="Brush.Contents" Color="White"/>
     <SolidColorBrush x:Key="Brush.Badge" Color="#FFAFAFAF"/>
-    <SolidColorBrush x:Key="Brush.CommitViewer" Color="#FFF0F0F0"/>
-    <SolidColorBrush x:Key="Brush.SideBar" Color="#FFF8F8F8"/>
     <SolidColorBrush x:Key="Brush.Decorator" Color="#FFBDBDBD"/>
     <SolidColorBrush x:Key="Brush.Conflict" Color="#FF836C2E"/>
 
@@ -18,7 +16,6 @@
     <SolidColorBrush x:Key="Brush.Border1" Color="#FF898989"/>
     <SolidColorBrush x:Key="Brush.Border2" Color="#FFCFCFCF"/>
     <SolidColorBrush x:Key="Brush.Border3" Color="#FFEFEFEF"/>
-    <SolidColorBrush x:Key="Brush.Border4" Color="#FFF2F2F2"/>
     
     <SolidColorBrush x:Key="Brush.FG1" Color="#FF1F1F1F"/>
     <SolidColorBrush x:Key="Brush.FG2" Color="#FF6F6F6F"/>

src/UI/Dashboard.xaml

@@ -108,7 +108,7 @@
         </Border>
 
         <!-- Main body -->
-        <Grid Grid.Row="1">
+        <Grid Grid.Row="1" Background="{StaticResource Brush.Window}">
             <Grid.ColumnDefinitions>
                 <ColumnDefinition Width="200" MinWidth="200" MaxWidth="300"/>
                 <ColumnDefinition Width="1"/>
@@ -116,7 +116,7 @@
             </Grid.ColumnDefinitions>
             
             <!-- Left panel -->
-            <Grid Grid.Column="0" x:Name="main" Background="{StaticResource Brush.SideBar}">
+            <Grid Grid.Column="0" x:Name="main">
                 <Grid.RowDefinitions>
                     <RowDefinition Height="24"/>
                     <RowDefinition Height="Auto"/>

src/UI/Histories.xaml

@@ -11,7 +11,7 @@
              xmlns:converters="clr-namespace:SourceGit.Converters"
              mc:Ignorable="d" 
              d:DesignHeight="450" d:DesignWidth="800">
-    <Grid x:Name="layout" Background="{StaticResource Brush.CommitViewer}">
+    <Grid x:Name="layout">
         <!-- List Panel (SearchBar + DataGrid) -->
         <Border x:Name="commitListPanel" Background="{StaticResource Brush.Contents}" BorderBrush="{StaticResource Brush.Border0}" SnapsToDevicePixels="True">
             <Grid>
@@ -185,7 +185,7 @@
             <local:TwoCommitsDiff x:Name="twoCommitDiff" Visibility="Collapsed"/>
 
             <!-- Mask -->
-            <Border x:Name="mask" Background="{StaticResource Brush.CommitViewer}">
+            <Border x:Name="mask" Background="{StaticResource Brush.Window}">
                 <StackPanel Orientation="Vertical" VerticalAlignment="Center" Opacity=".25">
                     <Path Width="128" Height="128" Data="{StaticResource Icon.Detail}"/>
                     <Label x:Name="txtCounter" Visibility="Hidden" FontFamily="Consolas" Margin="0,16,0,0" FontSize="24" FontWeight="UltraBold" HorizontalAlignment="Center"/>

src/UI/InteractiveRebase.xaml

@@ -182,13 +182,13 @@
             </Grid>
             
             <!-- Splitter -->
-            <GridSplitter Grid.Row="2" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="{StaticResource Brush.CommitViewer}"/>
+            <GridSplitter Grid.Row="2" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="{StaticResource Brush.Window}"/>
 
             <!-- Commit Detail -->
-            <local:CommitViewer x:Name="commitViewer" Grid.Row="3" Background="{StaticResource Brush.CommitViewer}"/>
+            <local:CommitViewer x:Name="commitViewer" Grid.Row="3" Background="{StaticResource Brush.Window}"/>
             
             <!-- Options Bar -->
-            <Grid Grid.Row="5" Background="{StaticResource Brush.CommitViewer}">
+            <Grid Grid.Row="5" Background="{StaticResource Brush.Window}">
                 <Grid.ColumnDefinitions>
                     <ColumnDefinition Width="*"/>
                     <ColumnDefinition Width="80"/>