Python SQL toolkit and ORM with modern query builder, relationship mapping, and async support.

• Supports SQLAlchemy 2.0 modern API with type hints, select() queries, and Mapped[T] declarative models; includes async support via AsyncSession and AsyncSessionLocal
• Covers one-to-many and many-to-many relationships with eager loading patterns (selectinload, joinedload) to prevent N+1 query problems
• Integrates with FastAPI via dependency injection, Alembic for schema migrations, and connection pooling with configurable pool size and recycling
• Includes CRUD operations, transaction management, batch operations, and testing patterns with pytest and in-memory SQLite