Psycopg-toolkit

Changes:

- Update README with comprehensive examples and usage guides
- Improve docstrings and code comments in core components
- Add advanced transaction and schema management examples
- Enhance error handling documentation
- Refactor and expand test coverage

Changes:

- Simplified Database and TransactionManager classes
- Added comprehensive error handling
- Improved connection pool management
- Updated project dependencies
- Enhanced test suite with test containers

Initial release of Psycopg Toolkit providing async-first PostgreSQL database management for Python.

**Features:**

Database:

- Async connection pooling via psycopg-pool
- Exponential backoff retry with configurable attempts
- Runtime pool optimization and health checks
- Automatic cleanup on shutdown

Transactions:

- Automatic rollback on errors
- Nested transaction support via savepoints
- Connection state management
- Integrated repository support

Repository Pattern:

- Generic type-safe CRUD operations
- Pydantic model integration
- Parameterized query building
- Bulk operation support

Requires Python 3.11+ and PostgreSQL 13+.