v0.13.116: v0.13.116

@newsroom.writer: CI owns the version: work commits carry no number; the release job picks it from the tags, stamps it, gates it, commits it as GitHub Actions, tags it and deploys that commit. release_stamp.py, the guard on version.txt, the pending version in validate.js and publish.py's replay; the rules in admin/notes/2026-10-27__ci-owns-the-version.md.