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.Tests/ViewModels/Dialogs/SitePickerDialogLogicTests.cs

@@ -0,0 +1,88 @@
+using System.ComponentModel;
+using SharepointToolbox.ViewModels.Dialogs;
+using SharepointToolbox.Views.Dialogs;
+using Xunit;
+
+namespace SharepointToolbox.Tests.ViewModels.Dialogs;
+
+public class SitePickerDialogLogicTests
+{
+    private static SitePickerItem Item(string url, string title, long sizeMb = 0, string template = "")
+        => new(url, title, sizeMb, 0, template);
+
+    [Fact]
+    public void ApplyFilter_TextFilter_MatchesUrlOrTitle_CaseInsensitive()
+    {
+        var items = new[]
+        {
+            Item("https://t/sites/hr", "HR Team"),
+            Item("https://t/sites/finance", "Finance"),
+        };
+
+        var result = SitePickerDialogLogic.ApplyFilter(items, "fINaNce", 0, long.MaxValue, "All").ToList();
+
+        Assert.Single(result);
+        Assert.Equal("Finance", result[0].Title);
+    }
+
+    [Fact]
+    public void ApplyFilter_SizeRange_FiltersInclusively()
+    {
+        var items = new[]
+        {
+            Item("a", "A", sizeMb: 100),
+            Item("b", "B", sizeMb: 500),
+            Item("c", "C", sizeMb: 1200),
+        };
+
+        var result = SitePickerDialogLogic.ApplyFilter(items, "", 100, 600, "All").ToList();
+
+        Assert.Equal(2, result.Count);
+        Assert.Contains(result, i => i.Title == "A");
+        Assert.Contains(result, i => i.Title == "B");
+    }
+
+    [Fact]
+    public void ApplyFilter_KindAll_SkipsKindCheck()
+    {
+        var items = new[] { Item("a", "A", template: "STS#3"), Item("b", "B", template: "GROUP#0") };
+
+        var result = SitePickerDialogLogic.ApplyFilter(items, "", 0, long.MaxValue, "All").ToList();
+
+        Assert.Equal(2, result.Count);
+    }
+
+    [Fact]
+    public void ApplySort_UnknownColumn_ReturnsInputUnchanged()
+    {
+        var items = new[] { Item("b", "B"), Item("a", "A") };
+
+        var result = SitePickerDialogLogic.ApplySort(items, "Nonexistent", ListSortDirection.Ascending).ToList();
+
+        Assert.Equal("B", result[0].Title);
+        Assert.Equal("A", result[1].Title);
+    }
+
+    [Fact]
+    public void ApplySort_Title_Ascending_And_Descending()
+    {
+        var items = new[] { Item("b", "B"), Item("a", "A"), Item("c", "C") };
+
+        var asc = SitePickerDialogLogic.ApplySort(items, "Title", ListSortDirection.Ascending).ToList();
+        var desc = SitePickerDialogLogic.ApplySort(items, "Title", ListSortDirection.Descending).ToList();
+
+        Assert.Equal(new[] { "A", "B", "C" }, asc.Select(i => i.Title));
+        Assert.Equal(new[] { "C", "B", "A" }, desc.Select(i => i.Title));
+    }
+
+    [Theory]
+    [InlineData("", 42L, 42L)]
+    [InlineData("   ", 42L, 42L)]
+    [InlineData("not-a-number", 42L, 42L)]
+    [InlineData("100", 42L, 100L)]
+    [InlineData("  100  ", 42L, 100L)]
+    public void ParseLongOrDefault_HandlesEmptyAndInvalid(string input, long fallback, long expected)
+    {
+        Assert.Equal(expected, SitePickerDialogLogic.ParseLongOrDefault(input, fallback));
+    }
+}