- Export Row class from __init__.py so users can type hint with it

- Extract decimal separator logic into decimal_config.py module

- Auto-export SQL/GetInfo/AuthType constants from constants.py

- Replace manual constant assignments in __init__.py with wildcard import

- Remove AuthType individual member exports to avoid namespace pollution

- Add test_row_export to verify Row class is properly exported

- Add test_get_info_constants to cover constants.py:530

- Add test_decimal_config_import_error_fallback for ImportError branch

- Remove unused Dict import from __init__.py

- Remove unreachable dead code in decimal_config.py

- Add pragma: no cover to TYPE_CHECKING guard