projection: publish clean MPLP public OSS main

[jearonwong]

Summary

Publishes the clean MPLP public OSS projection from the verified prerelease candidate into the final Public OSS repository.

Source chain:

1. Dev truth: Coregentis/MPLP-Protocol-Dev
2. Clean prerelease verification: Coregentis/mplp_prerelease@main
3. Final public PR source: external fork branch jearonwong/MPLP-Protocol:clean-public-oss-main-publication-20260609
4. Final target: Coregentis/MPLP-Protocol:main

This keeps Coregentis/MPLP-Protocol branch surface as main only.

Governance Boundary

• No GitHub Agents/Copilot Agent service used.
• No Public-hosted non-main branch created.
• No npm/PyPI mutation.
• No tag or GitHub Release mutation.
• No direct push to main.
• Merge is limited to this protected PR path after required gates pass.

Projection Gates

• Prerelease main verified clean after refresh.
• 768 tracked files.
• Forbidden path scan: 0.
• Local path / credential pattern scan: 0.
• Prerelease CodeQL and Docusaurus gates passed before this PR.