SA-206 predict demographic info

[lukeroantreeONS]

📌 Pull Request Template

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✨ Summary

Adds functionality to synthetic_responses module to have an LLM predict demographic characteristics based on survey response.
Intended use-case is for identifying where bias may manifest within other LLM interactions.

📜 Changes Introduced

• feat(synthetic_responses): adds construct_demographic_prediction_prompt() method
• feat(synthetic_responses): adds predict_demographic_info() method
• refactor(scripts): splits the synthetic-responses example script into two; one for answering follow-ups, one for predicting demographic information

✅ Checklist

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• Code is formatted using Black
• Imports are sorted using isort
• Code passes linting with Ruff, Pylint, and Mypy
• Security checks pass using Bandit
• API and Unit tests are written and pass using pytest
• Terraform files (if applicable) follow best practices and have been validated (terraform fmt & terraform validate)
• DocStrings follow Google-style and are added as per Pylint recommendations
• Documentation has been updated if needed

🔍 How to Test

run the sic vector store and survey assist API locally,
run the two example scripts in scripts/synthetic_responses/