fix: resolve post-milestone tech debt items

- Add DataGrid RowStyle with red highlighting for invalid CSV rows
  in BulkMembersView, BulkSitesView, and FolderStructureView
- Fix cancel test locale mismatch by setting EN culture before assertion
- Remove dead FeatureTabBase placeholder (replaced by full tab views)
- Clean up unused xmlns:controls from MainWindow.xaml

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

SharepointToolbox.Tests/ViewModels/FeatureViewModelBaseTests.cs

@@ -1,3 +1,4 @@
+using System.Globalization;
 using Microsoft.Extensions.Logging.Abstractions;
 using SharepointToolbox.Core.Models;
 using SharepointToolbox.ViewModels;
@@ -60,6 +61,11 @@ public class FeatureViewModelBaseTests
 
     [Fact]
     public async Task CancelCommand_DuringOperation_SetsStatusMessageToCancelled()
+    {
+        // Ensure EN culture so TranslationSource resolves "Operation cancelled"
+        var prev = CultureInfo.CurrentUICulture;
+        CultureInfo.CurrentUICulture = CultureInfo.GetCultureInfo("en");
+        try
         {
             var vm = new TestViewModel();
             var started = new TaskCompletionSource<bool>();
@@ -79,6 +85,11 @@ public class FeatureViewModelBaseTests
             Assert.Contains("cancel", vm.StatusMessage, StringComparison.OrdinalIgnoreCase);
             Assert.False(vm.IsRunning);
         }
+        finally
+        {
+            CultureInfo.CurrentUICulture = prev;
+        }
+    }
 
     [Fact]
     public async Task OperationCanceledException_IsCaughtGracefully_IsRunningBecomesFalse()

SharepointToolbox/MainWindow.xaml

@@ -4,7 +4,7 @@
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:loc="clr-namespace:SharepointToolbox.Localization"
-        xmlns:controls="clr-namespace:SharepointToolbox.Views.Controls"
+
         xmlns:views="clr-namespace:SharepointToolbox.Views.Tabs"
         mc:Ignorable="d"
         Title="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[app.title]}"
@@ -39,7 +39,7 @@
                  Background="Black" Foreground="LimeGreen"
                  FontFamily="Consolas" FontSize="11" />
 
-    <!-- TabControl: 7 stub tabs use FeatureTabBase; Settings tab wired in plan 01-07 -->
+    <!-- TabControl -->
     <TabControl>
       <TabItem x:Name="PermissionsTabItem"
                Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[tab.permissions]}">

SharepointToolbox/Views/Controls/FeatureTabBase.xaml

@@ -1,33 +0,0 @@
-<UserControl x:Class="SharepointToolbox.Views.Controls.FeatureTabBase"
-             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-             xmlns:loc="clr-namespace:SharepointToolbox.Localization">
-  <Grid>
-    <Grid.RowDefinitions>
-      <RowDefinition Height="*" />
-      <RowDefinition Height="Auto" />
-    </Grid.RowDefinitions>
-
-    <!-- Placeholder content — Phase 2+ replaces Row 0 -->
-    <TextBlock Grid.Row="0"
-               Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[tab.comingsoon]}"
-               HorizontalAlignment="Center" VerticalAlignment="Center" />
-
-    <!-- Per-tab progress/cancel strip (shown only when IsRunning) -->
-    <Grid Grid.Row="1" Margin="8,4"
-          Visibility="{Binding IsRunning, Converter={StaticResource BoolToVisibilityConverter}}">
-      <Grid.ColumnDefinitions>
-        <ColumnDefinition Width="*" />
-        <ColumnDefinition Width="Auto" />
-        <ColumnDefinition Width="Auto" />
-      </Grid.ColumnDefinitions>
-      <ProgressBar Grid.Column="0" Height="16" Minimum="0" Maximum="100"
-                   Value="{Binding ProgressValue}" />
-      <TextBlock Grid.Column="1" Margin="8,0" VerticalAlignment="Center"
-                 Text="{Binding StatusMessage}" />
-      <Button Grid.Column="2"
-              Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[btn.cancel]}"
-              Command="{Binding CancelCommand}" Width="70" />
-    </Grid>
-  </Grid>
-</UserControl>

SharepointToolbox/Views/Controls/FeatureTabBase.xaml.cs

@@ -1,11 +0,0 @@
-using System.Windows.Controls;
-
-namespace SharepointToolbox.Views.Controls;
-
-public partial class FeatureTabBase : UserControl
-{
-    public FeatureTabBase()
-    {
-        InitializeComponent();
-    }
-}

SharepointToolbox/Views/Tabs/BulkMembersView.xaml

@@ -33,6 +33,16 @@
         <!-- Preview DataGrid (Right) -->
         <DataGrid ItemsSource="{Binding PreviewRows}" AutoGenerateColumns="False"
                   IsReadOnly="True" CanUserSortColumns="True">
+            <DataGrid.RowStyle>
+                <Style TargetType="DataGridRow">
+                    <Style.Triggers>
+                        <DataTrigger Binding="{Binding IsValid}" Value="False">
+                            <Setter Property="Background" Value="#FFFDE0E0" />
+                            <Setter Property="Foreground" Value="#FFB00020" />
+                        </DataTrigger>
+                    </Style.Triggers>
+                </Style>
+            </DataGrid.RowStyle>
             <DataGrid.Columns>
                 <DataGridTextColumn Header="Valid" Binding="{Binding IsValid}" Width="50" />
                 <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulkmembers.groupname]}"

SharepointToolbox/Views/Tabs/BulkSitesView.xaml

@@ -31,6 +31,16 @@
 
         <DataGrid ItemsSource="{Binding PreviewRows}" AutoGenerateColumns="False"
                   IsReadOnly="True" CanUserSortColumns="True">
+            <DataGrid.RowStyle>
+                <Style TargetType="DataGridRow">
+                    <Style.Triggers>
+                        <DataTrigger Binding="{Binding IsValid}" Value="False">
+                            <Setter Property="Background" Value="#FFFDE0E0" />
+                            <Setter Property="Foreground" Value="#FFB00020" />
+                        </DataTrigger>
+                    </Style.Triggers>
+                </Style>
+            </DataGrid.RowStyle>
             <DataGrid.Columns>
                 <DataGridTextColumn Header="Valid" Binding="{Binding IsValid}" Width="50" />
                 <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulksites.name]}"

SharepointToolbox/Views/Tabs/FolderStructureView.xaml

@@ -38,6 +38,16 @@
 
         <DataGrid ItemsSource="{Binding PreviewRows}" AutoGenerateColumns="False"
                   IsReadOnly="True" CanUserSortColumns="True">
+            <DataGrid.RowStyle>
+                <Style TargetType="DataGridRow">
+                    <Style.Triggers>
+                        <DataTrigger Binding="{Binding IsValid}" Value="False">
+                            <Setter Property="Background" Value="#FFFDE0E0" />
+                            <Setter Property="Foreground" Value="#FFB00020" />
+                        </DataTrigger>
+                    </Style.Triggers>
+                </Style>
+            </DataGrid.RowStyle>
             <DataGrid.Columns>
                 <DataGridTextColumn Header="Valid" Binding="{Binding IsValid}" Width="50" />
                 <DataGridTextColumn Header="Level 1" Binding="{Binding Record.Level1}" Width="*" />