* fix(podcast): add fallback for models without json_object support (#747)
Models like Kimi K2 don't support response_format.type: json_object.
Add try-except to fall back to regular prompting with JSON parsing
when BadRequestError mentions json_object not supported.
- Add fallback to prompting + repair_json_output parsing
- Re-raise other BadRequestError types
- Add unit tests for script_writer_node with 100% coverage
* Apply suggestions from code review
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* fixes: the unit test error of test_script_writer_node.py
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
