为多个用户创建和管理独立的长期记忆文件，记录偏好和上下文并按用户名隔离存储。
- Initial release: Manage long-term memory files for multiple users. - Creates and maintains independent memory files per user, tracking preferences, context, and important info. - Automatically identifies users using the part of `sender_id` before the `|` symbol. - Provides APIs to get, save, append, and initialize user memory files. - Memory files are stored in Markdown format for each user in a dedicated directory, enabling easy editing and persistent user context.