feat: Refine 2fa (#11766)

* wip

* Update 2fa.qrdialog.vue

* Update 2fa.vue

* Update CHANGELOG.md

* tweak

* ✌️

packages/backend/src/server/api/endpoints/i/2fa/unregister.ts

@@ -46,6 +46,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 
 			await this.userProfilesRepository.update(me.id, {
 				twoFactorSecret: null,
+				twoFactorBackupSecret: null,
 				twoFactorEnabled: false,
 				usePasswordLessLogin: false,
 			});