refactor: Replace PnP commands with Graph in folder browser handler

MainForm.ps1

@@ -123,9 +123,9 @@ $btnBrowse.Add_Click({
         
         $selectedFolder = Get-FolderBrowser
         if ($selectedFolder) {
-            $webUrl = (Get-PnPWeb).ServerRelativeUrl
-            $relativePath = $selectedFolder.ServerRelativeUrl -replace [regex]::Escape($webUrl), ""
-            $script:txtFolder.Text = $relativePath.Trim('/')
+            # Use the ServerRelativeUrl directly from the folder browser
+            $script:txtFolder.Text = $selectedFolder.ServerRelativeUrl
+            $script:txtStatus.Text += "Selected folder: $($selectedFolder.ServerRelativeUrl)`n"
         }
     }
     catch {