Refactor CLI tests in `tests/test_main.py` to use `default_load_config_kwargs`

[szy196]

Background & Motivation

The load_config function in wptgen/config.py has been significantly refactored, adding numerous optional parameters to support new features (resume-from, state-dir, lightweight/reasoning models, etc.). Currently, many CLI tests in tests/test_main.py (like test_audit_success and test_chromestatus_command) perform partial assertions on the load_config call's keyword arguments.

While this approach works, it is less robust than performing a full comparison against a set of expected default values. A more maintainable pattern is to use a central fixture, such as default_load_config_kwargs, to provide a baseline of expected arguments and then override only the ones relevant to a specific test case.

Proposed Changes

• Update all CLI command tests in tests/test_main.py (e.g., test_generate_success, test_audit_success, test_chromestatus_command, test_list_models_command, etc.) to use mock_load_config.assert_called_once_with(**expected_kwargs).
• Ensure expected_kwargs is derived from a default_load_config_kwargs fixture to minimize boilerplate and improve consistency.
• Standardize the way CLI flags are validated to ensure all parameters are correctly passed to the configuration layer.

Acceptance Criteria

• test_audit_success uses assert_called_once_with with a full set of expected arguments.
• test_chromestatus_command uses assert_called_once_with with a full set of expected arguments.
• All other relevant tests in tests/test_main.py are refactored to use the same pattern.
• All tests in tests/test_main.py pass after the refactor.

_{This issue description was drafted by Gemini}