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/Services/Export/BulkResultCsvExportService.cs

@@ -2,20 +2,40 @@ using System.Globalization;
 using System.IO;
 using System.Text;
 using CsvHelper;
+using CsvHelper.Configuration;
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;
 
 namespace SharepointToolbox.Services.Export;
 
+/// <summary>
+/// Exports the failed subset of a <see cref="BulkOperationSummary{T}"/> run
+/// to CSV. CsvHelper is used so the <typeparamref name="T"/> payload's
+/// properties become columns automatically, plus one error-message and one
+/// timestamp column appended at the end.
+/// </summary>
 public class BulkResultCsvExportService
 {
+    private static readonly CsvConfiguration CsvConfig = new(CultureInfo.InvariantCulture)
+    {
+        // Prevent CSV formula injection: prefix =, +, -, @, tab, CR with single quote
+        InjectionOptions = InjectionOptions.Escape,
+    };
+
+    /// <summary>
+    /// Builds a CSV containing only items whose <see cref="BulkItemResult{T}.IsSuccess"/>
+    /// is <c>false</c>. Columns: every public property of <typeparamref name="T"/>
+    /// followed by Error and Timestamp (ISO-8601).
+    /// </summary>
     public string BuildFailedItemsCsv<T>(IReadOnlyList<BulkItemResult<T>> failedItems)
     {
+        var TL = TranslationSource.Instance;
         using var writer = new StringWriter();
-        using var csv = new CsvWriter(writer, CultureInfo.InvariantCulture);
+        using var csv = new CsvWriter(writer, CsvConfig);
 
         csv.WriteHeader<T>();
-        csv.WriteField("Error");
-        csv.WriteField("Timestamp");
+        csv.WriteField(TL["report.col.error"]);
+        csv.WriteField(TL["report.col.timestamp"]);
         csv.NextRecord();
 
         foreach (var item in failedItems.Where(r => !r.IsSuccess))
@@ -29,12 +49,13 @@ public class BulkResultCsvExportService
         return writer.ToString();
     }
 
+    /// <summary>Writes the failed-items CSV to <paramref name="filePath"/> with UTF-8 BOM.</summary>
     public async Task WriteFailedItemsCsvAsync<T>(
         IReadOnlyList<BulkItemResult<T>> failedItems,
         string filePath,
         CancellationToken ct)
     {
         var content = BuildFailedItemsCsv(failedItems);
-        await System.IO.File.WriteAllTextAsync(filePath, content, new UTF8Encoding(true), ct);
+        await ExportFileWriter.WriteCsvAsync(filePath, content, ct);
     }
 }