* Extract classes UserRepository and TaskRepository from PromptRepository
* move close_task() to TaskRepository and get_user_leaderboard to UserRepository()
* Use UserRepository in leaderboards endpoint, add type annotation to leaderboards endpoint
* Implement label task for initial prompts and replies
* Resolve formatting
* Include missing argument
* Modify text_labels API to match new model, update DB schema accordingly
* Send valid labels as part of label tasks
* Send correctly formatted valid_labels list
* Fix request format
* Fix request details for text-frontend reply label task
* Include message_id in tasks
* Address review comments
* Fix alembic tree