Add product buy auditor CLI

[PostgraduateAvi]

Summary

• add a standalone buy_auditor.py CLI that evaluates products against use-case rules and outputs Markdown/JSON/CSV reports
• include doctested utility helpers, rubric registry, and demo data for quick validation
• provide sample input files and documentation to exercise the tool

Testing

• python -m doctest buy_auditor.py
• python buy_auditor.py --input samples/products.json --usecase samples/usecase.json --weights samples/weights.json --top 2 --output reports

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https://chatgpt.com/codex/tasks/task_e_68dbedd5790c8321979f1884e557e4dc