WTI code-executing agent may omit json import before serializing results

[mbrotos]

Summary

The WTI code-executing agent generated a sandbox script that called json.dumps(results) without first importing json.

Reproduction

Run Step 4 of implementations/energy_oil_forecasting/02_intro_agentic_predictor.ipynb. A successful forecast run emitted:

NameError: name 'json' is not defined\n```\n\nThe final structured forecast was still returned, but the sandbox code execution reported an avoidable error.\n\n## Expected\n\nGenerated code should include all required imports.\n\n## Possible fix\n\nAdd an explicit instruction/example to import `json` whenever generated code serializes output with `json.dumps`.

[mbrotos]

This is likely due to the low coding capability of the default Gemini model used. Although prompting may help avoid some of these more common runtime errors.