docs: adopt doctrine project manifest

[shtse8]

Summary

• add repo-local AGENTS.md and PROJECT.md
• add .doctrine/project.json with lifecycle, boundaries, delivery proof, and npm package release facts

Validation

• python3 /Users/kyle/.doctrine/scripts/project-control-plane-audit.py --local /Users/kyle/.codex/worktrees/sylphx-silk-manifest --repo SylphxAI/silk --fail-on-drift --json
• python3 /Users/kyle/.doctrine/scripts/project-control-plane-audit.py --repo SylphxAI/silk --ref codex/project-manifest-adoption --fail-on-drift --json
• node JSON.parse .doctrine/project.json
• git diff --check

Notes

• Default branch currently reports 174 Dependabot vulnerabilities on push; this PR does not change dependencies.

[shtse8]

Control-plane manifest adoption was split out and merged via #5. This PR still contains SWC/Rust/test baseline changes and should be handled as product/CI repair, not as the manifest rollout blocker.