v12.7.0

• sync: new --changed-only true option to sync (and AI-auto-translate) only
  the keys that changed on the current git branch — ideal for translating just
  a pull request's diff instead of the whole project. The local
  reference-language files are diffed against the merge-base with the base
  branch (auto-detected via origin/HEAD, main, master, or set explicitly
  with --base <ref>), and key additions, value updates and auto-translation
  are restricted to those keys; deletions are skipped, since a branch's local
  files cannot see keys added remotely or by sibling branches in the meantime.
  Changed keys are scoped per namespace file (the same bare key name in two
  namespaces does not cross-match), and when any plural variant of a key
  changed, all its plural forms are included (target languages often need more
  CLDR plural forms than the source). Requires git; on shallow CI clones make
  sure the base branch is fetched (e.g. actions/checkout with
  fetch-depth: 0) — the error messages say exactly what is missing.