output_format + resume is broken (or unsupported) at the CLI level

- Task 1: structured_output type: dict — works, full audit returned
- Task 2: structured_output type: NoneType, value: None — CLI didn't return it. But the result field has plain text: the model
responded with regular text instead of JSON

So the --json-schema flag is not being enforced on resumed sessions. The CLI loads the prior session and the schema constraint
doesn't apply to the new turn. The model just answers in plain text.

This confirms: output_format + resume is broken (or unsupported) at the CLI level. The SDK passes both flags, but the CLI ignores
the schema on resume.