refactor: Update Get-FolderBrowser to use Graph API instead of PnP

SharePointFunctions.ps1

@@ -110,19 +110,35 @@ function Move-Files {
 }
 function Get-FolderBrowser {
     try {
-        # Verify library exists and is accessible
-        $library = Get-PnPList -Identity $script:txtProdLib.Text -Includes RootFolder,HasUniqueRoleAssignments
-        if ($library.HasUniqueRoleAssignments) {
-            throw "This library has unique permissions - verify app has access"
+        # Get site ID first
+        $siteUrl = $script:txtSiteUrl.Text
+        $site = Get-MgSite -Search $siteUrl | Where-Object { $_.WebUrl -eq $siteUrl }
+        
+        if (-not $site) {
+            throw "Site not found"
         }
+
+        # Get drive (document library)
+        $drives = Get-MgSiteDrive -SiteId $site.Id
+        $drive = $drives | Where-Object { $_.Name -eq $script:txtProdLib.Text }
         
-        # Get folders with elevated permissions
-        $ctx = Get-PnPContext
-        $ctx.Load($library.RootFolder.Folders)
-        $ctx.ExecuteQuery()
-        
-        return $library.RootFolder.Folders | 
-            Select-Object Name, ServerRelativeUrl |
+        if (-not $drive) {
+            throw "Library not found"
+        }
+
+        # Get folders
+        $folders = Get-MgDriveRoot -DriveId $drive.Id | Get-MgDriveItemChild -DriveId $drive.Id
+        $folders = $folders | Where-Object { $_.Folder }
+
+        # Create custom objects for the grid view
+        $folderObjects = $folders | ForEach-Object {
+            [PSCustomObject]@{
+                Name = $_.Name
+                ServerRelativeUrl = "/sites/$($site.Name)/$($drive.Name)/$($_.Name)"
+            }
+        }
+
+        return $folderObjects | 
             Out-GridView -Title "Select Folder" -PassThru
     }
     catch {