feat(08-02): add simplified mode properties to PermissionsViewModel

- IsSimplifiedMode toggle switches between raw and simplified labels
- IsDetailView toggle controls individual vs summary row display
- SimplifiedResults and Summaries computed from cached Results
- ActiveItemsSource provides correct collection for DataGrid binding
- Mode toggles rebuild from cache without re-running scan
- OnTenantSwitched resets simplified state

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

SharepointToolbox/ViewModels/Tabs/PermissionsViewModel.cs

@@ -9,6 +9,7 @@ using Microsoft.Win32;
 using SharepointToolbox.Core.Messages;
 using SharepointToolbox.Core.Models;
 using SharepointToolbox.Services;
+using SharepointToolbox.Core.Helpers;
 using SharepointToolbox.Services.Export;
 
 namespace SharepointToolbox.ViewModels.Tabs;
@@ -63,6 +64,51 @@ public partial class PermissionsViewModel : FeatureViewModelBase
     [ObservableProperty]
     private ObservableCollection<PermissionEntry> _results = new();
 
+    /// <summary>
+    /// When true, displays simplified plain-language labels instead of raw SharePoint role names.
+    /// Toggling does not re-run the scan.
+    /// </summary>
+    [ObservableProperty]
+    private bool _isSimplifiedMode;
+
+    /// <summary>
+    /// When true, shows individual item-level rows (detailed view).
+    /// When false, shows only summary rows grouped by risk level (simple view).
+    /// Only meaningful when IsSimplifiedMode is true.
+    /// </summary>
+    [ObservableProperty]
+    private bool _isDetailView = true;
+
+    /// <summary>
+    /// Simplified wrappers computed from Results. Rebuilt when Results changes.
+    /// </summary>
+    private IReadOnlyList<SimplifiedPermissionEntry> _simplifiedResults = Array.Empty<SimplifiedPermissionEntry>();
+    public IReadOnlyList<SimplifiedPermissionEntry> SimplifiedResults
+    {
+        get => _simplifiedResults;
+        private set => SetProperty(ref _simplifiedResults, value);
+    }
+
+    /// <summary>
+    /// Summary counts grouped by risk level. Rebuilt when SimplifiedResults changes.
+    /// </summary>
+    private IReadOnlyList<PermissionSummary> _summaries = Array.Empty<PermissionSummary>();
+    public IReadOnlyList<PermissionSummary> Summaries
+    {
+        get => _summaries;
+        private set => SetProperty(ref _summaries, value);
+    }
+
+    /// <summary>
+    /// The collection the DataGrid actually binds to. Returns:
+    /// - Results (raw) when simplified mode is OFF
+    /// - SimplifiedResults when simplified mode is ON and detail view is ON
+    /// - (View handles summary display separately via Summaries property)
+    /// </summary>
+    public object ActiveItemsSource => IsSimplifiedMode
+        ? (object)SimplifiedResults
+        : Results;
+
     partial void OnFolderDepthChanged(int value) => OnPropertyChanged(nameof(IsMaxDepth));
 
     // ── Commands ────────────────────────────────────────────────────────────
@@ -167,6 +213,28 @@ public partial class PermissionsViewModel : FeatureViewModelBase
             SelectedSites.Add(site);
     }
 
+    partial void OnIsSimplifiedModeChanged(bool value)
+    {
+        if (value && Results.Count > 0)
+            RebuildSimplifiedData();
+        OnPropertyChanged(nameof(ActiveItemsSource));
+    }
+
+    partial void OnIsDetailViewChanged(bool value)
+    {
+        OnPropertyChanged(nameof(ActiveItemsSource));
+    }
+
+    /// <summary>
+    /// Recomputes SimplifiedResults and Summaries from the current Results collection.
+    /// Called when Results changes or when simplified mode is toggled on.
+    /// </summary>
+    private void RebuildSimplifiedData()
+    {
+        SimplifiedResults = SimplifiedPermissionEntry.WrapAll(Results);
+        Summaries = PermissionSummaryBuilder.Build(SimplifiedResults);
+    }
+
     protected override async Task RunOperationAsync(CancellationToken ct, IProgress<OperationProgress> progress)
     {
         var urls = SelectedSites.Count > 0
@@ -213,11 +281,17 @@ public partial class PermissionsViewModel : FeatureViewModelBase
             await dispatcher.InvokeAsync(() =>
             {
                 Results = new ObservableCollection<PermissionEntry>(allEntries);
+                if (IsSimplifiedMode)
+                    RebuildSimplifiedData();
+                OnPropertyChanged(nameof(ActiveItemsSource));
             });
         }
         else
         {
             Results = new ObservableCollection<PermissionEntry>(allEntries);
+            if (IsSimplifiedMode)
+                RebuildSimplifiedData();
+            OnPropertyChanged(nameof(ActiveItemsSource));
         }
 
         ExportCsvCommand.NotifyCanExecuteChanged();
@@ -231,6 +305,9 @@ public partial class PermissionsViewModel : FeatureViewModelBase
         _currentProfile = profile;
         _hasLocalSiteOverride = false;
         Results = new ObservableCollection<PermissionEntry>();
+        SimplifiedResults = Array.Empty<SimplifiedPermissionEntry>();
+        Summaries = Array.Empty<PermissionSummary>();
+        OnPropertyChanged(nameof(ActiveItemsSource));
         SiteUrl = string.Empty;
         SelectedSites.Clear();
         OnPropertyChanged(nameof(SitesSelectedLabel));