build: Package referenced review evidence

[BenWestgate]

What

Include documentation CSV and JSON files in source distributions.

Why

The packaged alignment benchmark report links to CSV and JSON evidence that the current manifest omits. This adapts the earlier review-evidence packaging fix onto the current target so source releases remain self-contained for review.

The branch was refreshed onto the current reviewability-v1 after the BSD-3-Clause packaging fix landed. The resulting diff is again one focused MANIFEST.in line: it preserves recursive-include LICENSES * and adds only *.csv/*.json to the existing documentation include.

Validation

• python -m build --no-isolation
• python -m twine check dist/*
• python tools/verify_wheel_environment.py
• confirmed both referenced evidence files are present in the rebuilt sdist
• current head 9e4deb7 passes the full GitHub Actions matrix

[BenWestgate]

AI-generated review (Claude), posted at the maintainer's request.

ACK 9e4deb7

• The only docs/**/*.{csv,json} files are the two benchmark evidence files the report links.
• Merges cleanly with #54.