enhance: 通知の履歴をリセットできるように (#13335)

* enhance: 通知の履歴をリセットできるように

* Update Changelog

* 通知欄も連動して更新するように

* revert some changes

* Update CHANGELOG.md

* Remove unused part

* fix

packages/backend/src/core/NotificationService.ts

@@ -214,6 +214,15 @@ export class NotificationService implements OnApplicationShutdown {
 		*/
 	}
 
+	@bindThis
+	public async flushAllNotifications(userId: MiUser['id']) {
+		await Promise.all([
+			this.redisClient.del(`notificationTimeline:${userId}`),
+			this.redisClient.del(`latestReadNotification:${userId}`),
+		]);
+		this.globalEventService.publishMainStream(userId, 'notificationFlushed');
+	}
+
 	@bindThis
 	public dispose(): void {
 		this.#shutdownController.abort();