chore: release v2.4

- Add theme system (Dark/Light palettes, ModernTheme, ThemeManager)
- Add InputDialog, Spinner common view
- Add DuplicatesCsvExportService
- Refresh views, dialogs, and view models across tabs
- Update localization strings (en/fr)
- Tweak services (transfer, permissions, search, user access, ownership elevation, bulk operations)

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

SharepointToolbox/Views/Dialogs/FolderBrowserDialog.xaml

@@ -3,13 +3,23 @@
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:loc="clr-namespace:SharepointToolbox.Localization"
         Title="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[folderbrowser.title]}"
-        Width="400" Height="500" WindowStartupLocation="CenterOwner"
+        Width="520" Height="560" WindowStartupLocation="CenterOwner"
+        Background="{DynamicResource AppBgBrush}"
+        Foreground="{DynamicResource TextBrush}"
+        TextOptions.TextFormattingMode="Ideal"
         ResizeMode="CanResizeWithGrip">
     <DockPanel Margin="10">
         <!-- Status -->
         <TextBlock x:Name="StatusText" DockPanel.Dock="Top" Margin="0,0,0,10"
                    Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[folderbrowser.loading]}" />
 
+        <!-- Action bar: new folder (destination mode only) -->
+        <StackPanel x:Name="ActionBar" DockPanel.Dock="Top" Orientation="Horizontal"
+                    Margin="0,0,0,6" Visibility="Collapsed">
+            <Button x:Name="NewFolderButton" Content="+ New Folder"
+                    Padding="8,3" Click="NewFolder_Click" IsEnabled="False" />
+        </StackPanel>
+
         <!-- Buttons -->
         <StackPanel DockPanel.Dock="Bottom" Orientation="Horizontal"
                     HorizontalAlignment="Right" Margin="0,10,0,0">