changelog-maintenancelisted

# Changelog Maintenance ## Core Question How should the changelog be updated to reflect observed changes in the project’s existing format without inventing unsupported release information? ## When To Use Use this skill when the user asks to: - add or update `CHANGELOG.md` entries, - maintain an `Unreleased` section, - promote `Unreleased` to a version section, - validate changelog completeness, - categorize changes as added, changed, fixed, deprecated, removed, security, or breaking. ## When Not To Use Do not use this skill to draft polished release announcements, decide or edit versions, create tags, publish releases, push files, or create commits. Route to: - `release-notes` for user-facing release-note prose. - `version-bump` for version decisions or version file edits. - `tag-release` for Git tag creation. - a future `publish-release` skill or manual workflow for publication. - `atomic-commits` or `conventional-commits` for commit workflows. ## Required Evidence Inspect or establish: - existing changelog file and style, - project changelog conventions in README/CONTRIBUTING/release docs, - commit, PR, or issue evidence for requested range, - current version from version files when promoting a release section, - release date only when provided or evidenced, - breaking changes, migrations, deprecations, security claims, and performance claims only when evidenced, - duplicate entries already present. ## Operating Contract You MAY: - inspect changelog and relea