**Release notes now use [towncrier](https://towncrier.readthedocs.io) news fragments.** Each PR drops one tiny `changelog.d/<id>.<category>.md` file (categories: `breaking`, `security`, `feature`, `bugfix`, `removal`, `misc`). At release prep, the maintainer runs `pdm run towncrier build --version <X.Y.Z> --yes`, which renders the fragments into `docs/release_notes/<X.Y.Z>.md` and removes them. Replaces the previous shared-file workflow, which scaled poorly at LDR's PR throughput. See `changelog.d/README.md` for the convention.
