Batch hallucination-rate evaluation and reporting over a dataset

[zhenzhudingzhen528-cpu]

Summary

• JSONL and CSV input
• overall and grouped rates with explicit denominators
• span histograms and typed counts
• top-N flagged examples
• JSON and Markdown output
• network-free unit tests

Changed paths:

• scripts/report_hallucination_rates.py
• tests/test_report_hallucination_rates_pytest.py

Related issue

Closes #56.

Type of change

• Bug fix
• Feature
• Documentation
• Tests
• Refactor or maintenance

Testing

• python -m pytest tests/test_report_hallucination_rates_pytest.py -q — 23 passed
• ruff format --check
• ruff check
• git diff --check
• Other: current Windows full suite — 161 passed, 8 failed
• Other: recorded pre-change Windows baseline — 138 passed, 8 failed; recorded cause: existing Unix-only resource import in scripts/benchmark_detectors.py on Windows
• Exact failing test node IDs were not recorded, so failure-set equality was not verified.

Checklist

• I kept the PR focused on one change.
• I added or updated tests/docs when needed.
• I checked that no secrets, API keys, or credentials are included.

Rights & sign-off (required)

• I certify that I have the right to submit this code and that it may be distributed under the repository's MIT license. (attestation Only pyproject now, added ruff support, github workflows #1, mit-contribution-rights-v2)