fix: init notes before cleaning up notebooks

packages/core/collections/notebooks.js

@@ -131,7 +131,8 @@ export default class Notebooks extends Collection {
     }
   }
 
-  cleanup() {
+  async cleanup() {
+    await this._db.notes.init();
     for (let notebook of this.all) {
       for (let topic of notebook.topics) {
         const clonedIds = topic.notes.slice();

packages/core/database/backup.js

@@ -142,7 +142,7 @@ export default class Backup {
     ];
 
     if (await this._migrator.migrate(collections, (id) => data[id], version)) {
-      this._db.notebooks.cleanup();
+      await this._db.notebooks.cleanup();
     }
   }