feat(19-02): add app registration UI to profile dialog and 7 ViewModel tests

- ProfileManagementDialog.xaml: height 750, new Row 4 with Register/Remove buttons
- BooleanToVisibilityConverter added to Window.Resources
- Fallback instructions panel bound to ShowFallbackInstructions
- RegistrationStatus text block with StringToVisibilityConverter
- Buttons row shifted to Row 5
- ProfileManagementViewModelRegistrationTests: 7 unit tests, all passing
- ProfileManagementViewModelLogoTests: updated to 5-param constructor

SharepointToolbox.Tests/ViewModels/ProfileManagementViewModelLogoTests.cs

@@ -15,6 +15,7 @@ public class ProfileManagementViewModelLogoTests : IDisposable
 {
     private readonly string _tempFile;
     private readonly Mock<IBrandingService> _mockBranding;
+    private readonly Mock<IAppRegistrationService> _mockAppReg;
     private readonly GraphClientFactory _graphClientFactory;
     private readonly ILogger<ProfileManagementViewModel> _logger;
 
@@ -23,6 +24,7 @@ public class ProfileManagementViewModelLogoTests : IDisposable
         _tempFile = Path.GetTempFileName();
         File.Delete(_tempFile);
         _mockBranding = new Mock<IBrandingService>();
+        _mockAppReg = new Mock<IAppRegistrationService>();
         _graphClientFactory = new GraphClientFactory(new MsalClientFactory());
         _logger = NullLogger<ProfileManagementViewModel>.Instance;
     }
@@ -40,7 +42,8 @@ public class ProfileManagementViewModelLogoTests : IDisposable
             profileService,
             _mockBranding.Object,
             _graphClientFactory,
-            _logger);
+            _logger,
+            _mockAppReg.Object);
     }
 
     [Fact]
@@ -102,7 +105,8 @@ public class ProfileManagementViewModelLogoTests : IDisposable
             profileService,
             _mockBranding.Object,
             _graphClientFactory,
-            _logger);
+            _logger,
+            _mockAppReg.Object);
 
         vm.SelectedProfile = profile;
 
@@ -173,7 +177,8 @@ public class ProfileManagementViewModelLogoTests : IDisposable
             profileService,
             _mockBranding.Object,
             _graphClientFactory,
-            _logger);
+            _logger,
+            _mockAppReg.Object);
 
         vm.SelectedProfile = profile;
         Assert.NotNull(vm.ClientLogoPreview);

SharepointToolbox.Tests/ViewModels/ProfileManagementViewModelRegistrationTests.cs

@@ -0,0 +1,157 @@
+using System.IO;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using SharepointToolbox.Core.Models;
+using SharepointToolbox.Infrastructure.Auth;
+using SharepointToolbox.Infrastructure.Persistence;
+using SharepointToolbox.Services;
+using SharepointToolbox.ViewModels;
+
+namespace SharepointToolbox.Tests.ViewModels;
+
+[Trait("Category", "Unit")]
+public class ProfileManagementViewModelRegistrationTests : IDisposable
+{
+    private readonly string _tempFile;
+    private readonly Mock<IBrandingService> _mockBranding;
+    private readonly Mock<IAppRegistrationService> _mockAppReg;
+    private readonly GraphClientFactory _graphClientFactory;
+
+    public ProfileManagementViewModelRegistrationTests()
+    {
+        _tempFile = Path.GetTempFileName();
+        File.Delete(_tempFile);
+        _mockBranding = new Mock<IBrandingService>();
+        _mockAppReg = new Mock<IAppRegistrationService>();
+        _graphClientFactory = new GraphClientFactory(new MsalClientFactory());
+    }
+
+    public void Dispose()
+    {
+        if (File.Exists(_tempFile)) File.Delete(_tempFile);
+        if (File.Exists(_tempFile + ".tmp")) File.Delete(_tempFile + ".tmp");
+    }
+
+    private ProfileManagementViewModel CreateViewModel()
+    {
+        var profileService = new ProfileService(new ProfileRepository(_tempFile));
+        return new ProfileManagementViewModel(
+            profileService,
+            _mockBranding.Object,
+            _graphClientFactory,
+            NullLogger<ProfileManagementViewModel>.Instance,
+            _mockAppReg.Object);
+    }
+
+    private static TenantProfile MakeProfile(string? appId = null) => new TenantProfile
+    {
+        Name = "TestTenant",
+        TenantUrl = "https://test.sharepoint.com",
+        ClientId = "00000000-0000-0000-0000-000000000001",
+        AppId = appId
+    };
+
+    [Fact]
+    public void RegisterAppCommand_CanExecute_WhenProfileSelected_AndNoAppId()
+    {
+        var vm = CreateViewModel();
+        vm.SelectedProfile = MakeProfile(appId: null);
+
+        Assert.True(vm.RegisterAppCommand.CanExecute(null));
+    }
+
+    [Fact]
+    public void RegisterAppCommand_CannotExecute_WhenNoProfile()
+    {
+        var vm = CreateViewModel();
+
+        Assert.False(vm.RegisterAppCommand.CanExecute(null));
+    }
+
+    [Fact]
+    public void RemoveAppCommand_CanExecute_WhenProfileHasAppId()
+    {
+        var vm = CreateViewModel();
+        vm.SelectedProfile = MakeProfile(appId: "some-app-id");
+
+        Assert.True(vm.RemoveAppCommand.CanExecute(null));
+    }
+
+    [Fact]
+    public void RemoveAppCommand_CannotExecute_WhenNoAppId()
+    {
+        var vm = CreateViewModel();
+        vm.SelectedProfile = MakeProfile(appId: null);
+
+        Assert.False(vm.RemoveAppCommand.CanExecute(null));
+    }
+
+    [Fact]
+    public async Task RegisterApp_ShowsFallback_WhenNotAdmin()
+    {
+        _mockAppReg
+            .Setup(s => s.IsGlobalAdminAsync(It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(false);
+
+        var vm = CreateViewModel();
+        vm.SelectedProfile = MakeProfile(appId: null);
+
+        await vm.RegisterAppCommand.ExecuteAsync(null);
+
+        Assert.True(vm.ShowFallbackInstructions);
+    }
+
+    [Fact]
+    public async Task RegisterApp_SetsAppId_OnSuccess()
+    {
+        _mockAppReg
+            .Setup(s => s.IsGlobalAdminAsync(It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(true);
+        _mockAppReg
+            .Setup(s => s.RegisterAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(AppRegistrationResult.Success("new-app-id-123"));
+
+        var profileService = new ProfileService(new ProfileRepository(_tempFile));
+        var profile = MakeProfile(appId: null);
+        await profileService.AddProfileAsync(profile);
+
+        var vm = new ProfileManagementViewModel(
+            profileService,
+            _mockBranding.Object,
+            _graphClientFactory,
+            NullLogger<ProfileManagementViewModel>.Instance,
+            _mockAppReg.Object);
+        vm.SelectedProfile = profile;
+
+        await vm.RegisterAppCommand.ExecuteAsync(null);
+
+        Assert.Equal("new-app-id-123", profile.AppId);
+    }
+
+    [Fact]
+    public async Task RemoveApp_ClearsAppId()
+    {
+        _mockAppReg
+            .Setup(s => s.RemoveAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .Returns(Task.CompletedTask);
+        _mockAppReg
+            .Setup(s => s.ClearMsalSessionAsync(It.IsAny<string>(), It.IsAny<string>()))
+            .Returns(Task.CompletedTask);
+
+        var profileService = new ProfileService(new ProfileRepository(_tempFile));
+        var profile = MakeProfile(appId: "existing-app-id");
+        await profileService.AddProfileAsync(profile);
+
+        var vm = new ProfileManagementViewModel(
+            profileService,
+            _mockBranding.Object,
+            _graphClientFactory,
+            NullLogger<ProfileManagementViewModel>.Instance,
+            _mockAppReg.Object);
+        vm.SelectedProfile = profile;
+
+        await vm.RemoveAppCommand.ExecuteAsync(null);
+
+        Assert.Null(profile.AppId);
+    }
+}

SharepointToolbox/Views/Dialogs/ProfileManagementDialog.xaml

@@ -2,9 +2,12 @@
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:loc="clr-namespace:SharepointToolbox.Localization"
-        Title="Manage Profiles" Width="500" Height="620"
+        Title="Manage Profiles" Width="500" Height="750"
         WindowStartupLocation="CenterOwner" ShowInTaskbar="False"
         ResizeMode="NoResize">
+  <Window.Resources>
+    <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />
+  </Window.Resources>
   <Grid Margin="12">
     <Grid.RowDefinitions>
       <RowDefinition Height="Auto" />
@@ -12,6 +15,7 @@
       <RowDefinition Height="Auto" />
       <RowDefinition Height="Auto" />
       <RowDefinition Height="Auto" />
+      <RowDefinition Height="Auto" />
     </Grid.RowDefinitions>
 
     <!-- Profile list -->
@@ -83,8 +87,47 @@
                  Visibility="{Binding ValidationMessage, Converter={StaticResource StringToVisibilityConverter}}" />
     </StackPanel>
 
+    <!-- App Registration -->
+    <StackPanel Grid.Row="4" Margin="0,8,0,8">
+      <Label Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.fallback.title]}"
+             FontWeight="SemiBold" Padding="0,0,0,4"
+             Visibility="{Binding ShowFallbackInstructions, Converter={StaticResource BooleanToVisibilityConverter}}" />
+
+      <!-- Register / Remove buttons -->
+      <StackPanel Orientation="Horizontal" Margin="0,0,0,4">
+        <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.register]}"
+                Command="{Binding RegisterAppCommand}" Width="120" Margin="0,0,8,0" />
+        <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.remove]}"
+                Command="{Binding RemoveAppCommand}" Width="120" Margin="0,0,8,0" />
+      </StackPanel>
+
+      <!-- Status text -->
+      <TextBlock Text="{Binding RegistrationStatus}" FontSize="11" Margin="0,2,0,0"
+                 Foreground="#006600"
+                 Visibility="{Binding RegistrationStatus, Converter={StaticResource StringToVisibilityConverter}}" />
+
+      <!-- Fallback instructions panel -->
+      <Border BorderBrush="#DDDDDD" BorderThickness="1" Padding="8" CornerRadius="4" Margin="0,4,0,0"
+              Visibility="{Binding ShowFallbackInstructions, Converter={StaticResource BooleanToVisibilityConverter}}">
+        <StackPanel>
+          <TextBlock Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.fallback.step1]}"
+                     TextWrapping="Wrap" Margin="0,2" />
+          <TextBlock Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.fallback.step2]}"
+                     TextWrapping="Wrap" Margin="0,2" />
+          <TextBlock Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.fallback.step3]}"
+                     TextWrapping="Wrap" Margin="0,2" />
+          <TextBlock Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.fallback.step4]}"
+                     TextWrapping="Wrap" Margin="0,2" />
+          <TextBlock Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.fallback.step5]}"
+                     TextWrapping="Wrap" Margin="0,2" />
+          <TextBlock Text="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.fallback.step6]}"
+                     TextWrapping="Wrap" Margin="0,2" />
+        </StackPanel>
+      </Border>
+    </StackPanel>
+
     <!-- Buttons -->
-    <StackPanel Grid.Row="4" Orientation="Horizontal" HorizontalAlignment="Right">
+    <StackPanel Grid.Row="5" Orientation="Horizontal" HorizontalAlignment="Right">
       <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.add]}"
               Command="{Binding AddCommand}" Width="60" Margin="4,0" />
       <Button Content="{Binding Source={x:Static loc:TranslationSource.Instance}, Path=[profile.rename]}"