.github/workflows/build.yml just ran clean end to end on both ubuntu-latest and windows-latest (build, full test suite, native shim compilation, headless physics verification) after fixing the two real cross-platform bugs its first run caught. Updating README/kernel-contract to say so instead of "pending." Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N