* add /api/v1/users/{user_id}/stats endpoint
* return 0 stats and add /api/v1/users/{user_id}/stats/{time_frame}
* use utcnow() as modified date for 0 stats
* Add endpoints for getting, updating, deleting users by global user ID
* Resolve formatting
* Include alembic revision script
* Updated down_revision to current alembic head
Co-authored-by: Andreas Köpf <andreas.koepf@xamla.com>
* 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