Ad and purchases enabled (still need actual testing)

lib/services/cloud/google_drive_provider.dart

@@ -157,6 +157,20 @@ class GoogleDriveSession implements CloudStorageSession {
     return created.id!;
   }
 
+  @override
+  Future<String> moveFolder({required String folderId, required String newParentId}) async {
+    final current = await _api.files.get(folderId, $fields: 'parents') as drive.File;
+    final oldParents = (current.parents ?? []).join(',');
+    final updated = await _api.files.update(
+      drive.File(),
+      folderId,
+      addParents: newParentId,
+      removeParents: oldParents.isEmpty ? null : oldParents,
+      $fields: 'id',
+    );
+    return updated.id ?? folderId;
+  }
+
   @override
   Future<CloudFileInfo?> findFile({required String folderId, required String name}) async {
     final result = await _api.files.list(