- Introduced extensive tests for session cleanup, async session CRUD methods, and concurrent cleanup to ensure reliability and efficiency.
- Enhanced `schemas/users.py` with reusable password strength validation logic.
- Improved error handling in `admin.py` routes by replacing `detail` with `message` for consistency and readability.
- Introduced `user_sessions` table with support for per-device authentication sessions.
- Added `UserSession` model, including fields for device metadata, IP, and session state.
- Created schemas (`SessionBase`, `SessionCreate`, `SessionResponse`) to manage session data and responses.
- Implemented utilities for extracting and parsing device information from HTTP requests.
- Added Alembic migration to define `user_sessions` table with indexes for performance and cleanup.
