## Situation
_What's the context and the problem this addresses?_
## Task
_What does this PR set out to do?_
## Action
_What changes were made?_
## Result
_What's the outcome — tests, benchmarks, behavior?_
---
- [ ] `cargo fmt --all -- --check` passes
- [ ] `cargo clippy --all-targets -- -D warnings` passes
- [ ] `cargo test` passes
- [ ] Conventional commits; one commit per logical change
- [ ] No code comments; `ROADMAP.md` / `CHANGELOG.md` updated for any user-visible change