fix: restore .value access when using -AllPages on group queries

Invoke-GraphRequest with -AllPages returns the full response object
with accumulated items in .value, not a flat array.

Scripts/Backup-Restore-Assignments.ps1

@@ -279,7 +279,7 @@ if($Mode -eq "Backup")
     Write-Host "`nLoading groups for backup resolution..." -ForegroundColor Cyan
     $backupGroupsResponse = Invoke-GraphRequest "/groups?`$select=id,displayName&`$orderby=displayName" -AllPages
     $backupGroups = @{}
-    foreach($g in $backupGroupsResponse)
+    foreach($g in $backupGroupsResponse.value)
     {
         $backupGroups[$g.id] = $g.displayName
     }
@@ -383,7 +383,7 @@ elseif($Mode -eq "Restore")
     # Resolve group names to IDs in current tenant if needed
     Write-Host "`nLoading current tenant groups for name resolution..." -ForegroundColor Cyan
     $currentGroupsResponse = Invoke-GraphRequest "/groups?`$select=id,displayName&`$orderby=displayName" -AllPages
-    $currentGroups = $currentGroupsResponse
+    $currentGroups = $currentGroupsResponse.value
 
     $success = 0
     $skipped = 0