The plugins monorepo's sunset rule ('delete a bundled fallback copy only
when the manifest floors on the first core release shipping the module')
needs core module additions recorded against version numbers. Seeds the
changelog at 3.1.0 and documents the discipline.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FgbA8SMutQQpXkMG8LMmC4
