167/175 gain '### Added', 173/178 '### Changed', 180 '### Fixed' — every
bullet byte-identical, headings only (the #158 bar, inverted). CONSUMERS.md
names the sentinel and the flip procedure; changelog.d/README.md names the
sentinel. 182.md is this PR's own fragment, grouped atop the sentinel it
ships.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The flip's mechanical half (#117): the 26 entries under '## Unreleased'
move verbatim to changelog.d/<issue>.md, the heading is deleted, the
directory gains its marker README (#112 D1) and this PR's own fragment
(112.md), CHANGELOG.md's preamble describes fragments, and labeler.yml
maps changelog.d/** into scope:release-flow.
