Add Licensing section to CONTRIBUTING.md explaining:
- Dual MIT OR Apache-2.0 licensing model
- Apache NOTICE file policy (optional for upstream, redistributors MAY add)
- Attribution guidelines for downstream redistributors
Also add verification note confirming all acceptance criteria PASS:
- LICENSE-MIT and LICENSE-APACHE files present at repo root
- All workspace crates declare "MIT OR Apache-2.0" license
- cargo deny check licenses passes (implicit deny-by-default via allow list)
- Binary and wheel distributions configured to include both license files
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
