feat(16-01): add MergePermissions property to both ViewModels and localization keys

- Added [ObservableProperty] _mergePermissions (defaults false) to UserAccessAuditViewModel
- Added [ObservableProperty] _mergePermissions (no-op placeholder) to PermissionsViewModel
- Added audit.grp.export and chk.merge.permissions keys to Strings.resx (EN)
- Added audit.grp.export and chk.merge.permissions keys to Strings.fr.resx (FR)

SharepointToolbox/Localization/Strings.fr.resx

@@ -409,4 +409,7 @@
   <data name="directory.col.department" xml:space="preserve"><value>D&#233;partement</value></data>
   <data name="directory.col.jobtitle" xml:space="preserve"><value>Poste</value></data>
   <data name="directory.col.type" xml:space="preserve"><value>Type</value></data>
+  <!-- Phase 16: Report Consolidation Toggle -->
+  <data name="audit.grp.export" xml:space="preserve"><value>Options d'exportation</value></data>
+  <data name="chk.merge.permissions" xml:space="preserve"><value>Fusionner les permissions en double</value></data>
 </root>

SharepointToolbox/Localization/Strings.resx

@@ -409,4 +409,7 @@
   <data name="directory.col.department" xml:space="preserve"><value>Department</value></data>
   <data name="directory.col.jobtitle" xml:space="preserve"><value>Job Title</value></data>
   <data name="directory.col.type" xml:space="preserve"><value>Type</value></data>
+  <!-- Phase 16: Report Consolidation Toggle -->
+  <data name="audit.grp.export" xml:space="preserve"><value>Export Options</value></data>
+  <data name="chk.merge.permissions" xml:space="preserve"><value>Merge duplicate permissions</value></data>
 </root>

SharepointToolbox/ViewModels/Tabs/PermissionsViewModel.cs

@@ -37,6 +37,10 @@ public partial class PermissionsViewModel : FeatureViewModelBase
     [ObservableProperty]
     private bool _scanFolders = true;
 
+    /// <summary>Placeholder for the Export Options toggle — no-op in PermissionsViewModel (reserved for future use).</summary>
+    [ObservableProperty]
+    private bool _mergePermissions;
+
     [ObservableProperty]
     private bool _includeSubsites;
 

SharepointToolbox/ViewModels/Tabs/UserAccessAuditViewModel.cs

@@ -101,6 +101,10 @@ public partial class UserAccessAuditViewModel : FeatureViewModelBase
     [ObservableProperty]
     private string _directoryFilterText = string.Empty;
 
+    /// <summary>When true, the CSV export merges duplicate permission rows into consolidated entries.</summary>
+    [ObservableProperty]
+    private bool _mergePermissions;
+
     private CancellationTokenSource? _directoryCts = null;
 
     // ── Computed summary properties ─────────────────────────────────────────