feat(04-09): create BulkMembers, BulkSites, and FolderStructure ViewModels and Views

- BulkMembersViewModel: CSV import, validate, preview, confirm, execute, retry failed, export failed
- BulkSitesViewModel: same flow using IBulkSiteService.CreateSitesAsync
- FolderStructureViewModel: site URL + library inputs, CSV folders, FolderStructureService.BuildUniquePaths
- BulkMembersView/BulkSitesView/FolderStructureView: XAML + code-behind wiring ConfirmBulkOperationDialog
- [Rule 3] Fixed duplicate converter definitions: removed untracked standalone EnumBoolConverter/StringToVisibilityConverter/ListToStringConverter files (already defined in IndentConverter.cs)

SharepointToolbox/Views/Tabs/BulkMembersView.xaml

@@ -0,0 +1,50 @@
+<UserControl x:Class="SharepointToolbox.Views.Tabs.BulkMembersView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:loc="clr-namespace:SharepointToolbox.Localization">
+    <DockPanel Margin="10">
+        <!-- Options Panel (Left) -->
+        <StackPanel DockPanel.Dock="Left" Width="240" Margin="0,0,10,0">
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulkmembers.import]}"
+                    Command="{Binding ImportCsvCommand}" Margin="0,0,0,5" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulkmembers.example]}"
+                    Command="{Binding LoadExampleCommand}" Margin="0,0,0,10" />
+
+            <TextBlock Text="{Binding PreviewSummary}" TextWrapping="Wrap" Margin="0,0,0,10" />
+
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulkmembers.execute]}"
+                    Command="{Binding RunCommand}" Margin="0,0,0,5"
+                    IsEnabled="{Binding IsRunning, Converter={StaticResource InverseBoolConverter}}" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[status.cancelled]}"
+                    Command="{Binding CancelCommand}"
+                    Visibility="{Binding IsRunning, Converter={StaticResource BoolToVisibilityConverter}}" />
+
+            <ProgressBar Height="20" Margin="0,10,0,5" Value="{Binding ProgressValue}"
+                         Visibility="{Binding IsRunning, Converter={StaticResource BoolToVisibilityConverter}}" />
+            <TextBlock Text="{Binding StatusMessage}" TextWrapping="Wrap" />
+
+            <TextBlock Text="{Binding ResultSummary}" FontWeight="Bold" Margin="0,10,0,5" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulk.retryfailed]}"
+                    Command="{Binding RetryFailedCommand}" Margin="0,0,0,5" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulk.exportfailed]}"
+                    Command="{Binding ExportFailedCommand}" />
+        </StackPanel>
+
+        <!-- Preview DataGrid (Right) -->
+        <DataGrid ItemsSource="{Binding PreviewRows}" AutoGenerateColumns="False"
+                  IsReadOnly="True" CanUserSortColumns="True">
+            <DataGrid.Columns>
+                <DataGridTextColumn Header="Valid" Binding="{Binding IsValid}" Width="50" />
+                <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulkmembers.groupname]}"
+                                    Binding="{Binding Record.GroupName}" Width="*" />
+                <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulkmembers.email]}"
+                                    Binding="{Binding Record.Email}" Width="*" />
+                <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulkmembers.role]}"
+                                    Binding="{Binding Record.Role}" Width="80" />
+                <DataGridTextColumn Header="Errors"
+                                    Binding="{Binding Errors, Converter={StaticResource ListToStringConverter}}"
+                                    Width="*" />
+            </DataGrid.Columns>
+        </DataGrid>
+    </DockPanel>
+</UserControl>

SharepointToolbox/Views/Tabs/BulkMembersView.xaml.cs

@@ -0,0 +1,21 @@
+using System.Windows.Controls;
+using SharepointToolbox.Views.Dialogs;
+
+namespace SharepointToolbox.Views.Tabs;
+
+public partial class BulkMembersView : UserControl
+{
+    public BulkMembersView(ViewModels.Tabs.BulkMembersViewModel viewModel)
+    {
+        InitializeComponent();
+        DataContext = viewModel;
+
+        viewModel.ShowConfirmDialog = message =>
+        {
+            var dlg = new ConfirmBulkOperationDialog(message)
+                { Owner = System.Windows.Window.GetWindow(this) };
+            dlg.ShowDialog();
+            return dlg.IsConfirmed;
+        };
+    }
+}

SharepointToolbox/Views/Tabs/BulkSitesView.xaml

@@ -0,0 +1,50 @@
+<UserControl x:Class="SharepointToolbox.Views.Tabs.BulkSitesView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:loc="clr-namespace:SharepointToolbox.Localization">
+    <DockPanel Margin="10">
+        <StackPanel DockPanel.Dock="Left" Width="240" Margin="0,0,10,0">
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulksites.import]}"
+                    Command="{Binding ImportCsvCommand}" Margin="0,0,0,5" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulksites.example]}"
+                    Command="{Binding LoadExampleCommand}" Margin="0,0,0,10" />
+
+            <TextBlock Text="{Binding PreviewSummary}" TextWrapping="Wrap" Margin="0,0,0,10" />
+
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulksites.execute]}"
+                    Command="{Binding RunCommand}" Margin="0,0,0,5"
+                    IsEnabled="{Binding IsRunning, Converter={StaticResource InverseBoolConverter}}" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[status.cancelled]}"
+                    Command="{Binding CancelCommand}"
+                    Visibility="{Binding IsRunning, Converter={StaticResource BoolToVisibilityConverter}}" />
+
+            <ProgressBar Height="20" Margin="0,10,0,5" Value="{Binding ProgressValue}"
+                         Visibility="{Binding IsRunning, Converter={StaticResource BoolToVisibilityConverter}}" />
+            <TextBlock Text="{Binding StatusMessage}" TextWrapping="Wrap" />
+
+            <TextBlock Text="{Binding ResultSummary}" FontWeight="Bold" Margin="0,10,0,5" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulk.retryfailed]}"
+                    Command="{Binding RetryFailedCommand}" Margin="0,0,0,5" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulk.exportfailed]}"
+                    Command="{Binding ExportFailedCommand}" />
+        </StackPanel>
+
+        <DataGrid ItemsSource="{Binding PreviewRows}" AutoGenerateColumns="False"
+                  IsReadOnly="True" CanUserSortColumns="True">
+            <DataGrid.Columns>
+                <DataGridTextColumn Header="Valid" Binding="{Binding IsValid}" Width="50" />
+                <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulksites.name]}"
+                                    Binding="{Binding Record.Name}" Width="*" />
+                <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulksites.alias]}"
+                                    Binding="{Binding Record.Alias}" Width="100" />
+                <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulksites.type]}"
+                                    Binding="{Binding Record.Type}" Width="100" />
+                <DataGridTextColumn Header="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulksites.owners]}"
+                                    Binding="{Binding Record.Owners}" Width="*" />
+                <DataGridTextColumn Header="Errors"
+                                    Binding="{Binding Errors, Converter={StaticResource ListToStringConverter}}"
+                                    Width="*" />
+            </DataGrid.Columns>
+        </DataGrid>
+    </DockPanel>
+</UserControl>

SharepointToolbox/Views/Tabs/BulkSitesView.xaml.cs

@@ -0,0 +1,21 @@
+using System.Windows.Controls;
+using SharepointToolbox.Views.Dialogs;
+
+namespace SharepointToolbox.Views.Tabs;
+
+public partial class BulkSitesView : UserControl
+{
+    public BulkSitesView(ViewModels.Tabs.BulkSitesViewModel viewModel)
+    {
+        InitializeComponent();
+        DataContext = viewModel;
+
+        viewModel.ShowConfirmDialog = message =>
+        {
+            var dlg = new ConfirmBulkOperationDialog(message)
+                { Owner = System.Windows.Window.GetWindow(this) };
+            dlg.ShowDialog();
+            return dlg.IsConfirmed;
+        };
+    }
+}

SharepointToolbox/Views/Tabs/FolderStructureView.xaml

@@ -0,0 +1,53 @@
+<UserControl x:Class="SharepointToolbox.Views.Tabs.FolderStructureView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:loc="clr-namespace:SharepointToolbox.Localization">
+    <DockPanel Margin="10">
+        <StackPanel DockPanel.Dock="Left" Width="280" Margin="0,0,10,0">
+            <!-- Site URL and Library inputs -->
+            <TextBlock Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[folderstruct.siteurl]}"
+                       Margin="0,0,0,3" />
+            <TextBox Text="{Binding SiteUrl, UpdateSourceTrigger=PropertyChanged}" Margin="0,0,0,10" />
+
+            <TextBlock Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[folderstruct.library]}"
+                       Margin="0,0,0,3" />
+            <TextBox Text="{Binding LibraryTitle, UpdateSourceTrigger=PropertyChanged}" Margin="0,0,0,10" />
+
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[folderstruct.import]}"
+                    Command="{Binding ImportCsvCommand}" Margin="0,0,0,5" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[folderstruct.example]}"
+                    Command="{Binding LoadExampleCommand}" Margin="0,0,0,10" />
+
+            <TextBlock Text="{Binding PreviewSummary}" TextWrapping="Wrap" Margin="0,0,0,10" />
+
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[folderstruct.execute]}"
+                    Command="{Binding RunCommand}" Margin="0,0,0,5"
+                    IsEnabled="{Binding IsRunning, Converter={StaticResource InverseBoolConverter}}" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[status.cancelled]}"
+                    Command="{Binding CancelCommand}"
+                    Visibility="{Binding IsRunning, Converter={StaticResource BoolToVisibilityConverter}}" />
+
+            <ProgressBar Height="20" Margin="0,10,0,5" Value="{Binding ProgressValue}"
+                         Visibility="{Binding IsRunning, Converter={StaticResource BoolToVisibilityConverter}}" />
+            <TextBlock Text="{Binding StatusMessage}" TextWrapping="Wrap" />
+
+            <TextBlock Text="{Binding ResultSummary}" FontWeight="Bold" Margin="0,10,0,5" />
+            <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[bulk.exportfailed]}"
+                    Command="{Binding ExportFailedCommand}" />
+        </StackPanel>
+
+        <DataGrid ItemsSource="{Binding PreviewRows}" AutoGenerateColumns="False"
+                  IsReadOnly="True" CanUserSortColumns="True">
+            <DataGrid.Columns>
+                <DataGridTextColumn Header="Valid" Binding="{Binding IsValid}" Width="50" />
+                <DataGridTextColumn Header="Level 1" Binding="{Binding Record.Level1}" Width="*" />
+                <DataGridTextColumn Header="Level 2" Binding="{Binding Record.Level2}" Width="*" />
+                <DataGridTextColumn Header="Level 3" Binding="{Binding Record.Level3}" Width="*" />
+                <DataGridTextColumn Header="Level 4" Binding="{Binding Record.Level4}" Width="*" />
+                <DataGridTextColumn Header="Errors"
+                                    Binding="{Binding Errors, Converter={StaticResource ListToStringConverter}}"
+                                    Width="*" />
+            </DataGrid.Columns>
+        </DataGrid>
+    </DockPanel>
+</UserControl>

SharepointToolbox/Views/Tabs/FolderStructureView.xaml.cs

@@ -0,0 +1,21 @@
+using System.Windows.Controls;
+using SharepointToolbox.Views.Dialogs;
+
+namespace SharepointToolbox.Views.Tabs;
+
+public partial class FolderStructureView : UserControl
+{
+    public FolderStructureView(ViewModels.Tabs.FolderStructureViewModel viewModel)
+    {
+        InitializeComponent();
+        DataContext = viewModel;
+
+        viewModel.ShowConfirmDialog = message =>
+        {
+            var dlg = new ConfirmBulkOperationDialog(message)
+                { Owner = System.Windows.Window.GetWindow(this) };
+            dlg.ShowDialog();
+            return dlg.IsConfirmed;
+        };
+    }
+}