BrittleBench protocol lock v1.0.0

Protocol lock\n\nThis release is the public timestamped lock record for the BrittleBench Phase 1 research protocol.\n\n- Protocol version: v1.0.0\n- Lock date: 2026-05-25\n- Status: LOCKED\n- Canonical file: PROTOCOL.md\n- Commit: 7f8944c\n\nPost-lock methodology changes require a new major protocol version and logged DECISIONS.md and CHANGELOG.md entries.\n\n## Validation\n\n- Docusaurus production build passed locally with npm run build\n- git diff --check passed\n- No execution-phase corpus/data directories are tracked in this release