[moruku36]

Summary

Fix the optional-format guard in test_list to check the parametrized output_format rather than Python's builtin format.

Previously the guard was always true, so even the None row appended --format instead of exercising option omission. The corrected guard makes that row cover the CLI's default format; all ten existing parametrization rows and assertions are unchanged.

This is a test-coverage correction only; no production code changes.

Verification

• Independent static review approved the one-line change.
• Runtime pytest verification is unconfirmed: the validation worker timed out without a recoverable terminal result. No passing test result is claimed, and the uncertain invocation was not repeated.