The release workflow failed for v2.16.0 because
extract-release-notes.sh looked for docs/CHANGELOG.md, which was
stale. The root CHANGELOG.md is the source of truth.
Declutter repo root — keep only AGENTS.md, CLAUDE.md, README.md, LICENSE,
GOALS.yaml, PRODUCT.md at top level. All cross-references updated across
README, .github templates, docs/, scripts/, skills/, and tests/.