Describe the change and its intent.
- Bug fix
- New feature
- Refactor
- Documentation
- Spec alignment / conformance change
- CI passes (build/test/fmt/clippy)
- Tests updated or added
- Fixtures / goldens updated (if runtime behavior changes)
- No unintended breaking changes
- Spec impact reviewed (if applicable)
Add any extra context: design decisions, alternatives considered, risks.