* ci: sync changed skills to ClawHub on push to main
Add a GitHub Actions workflow that runs `clawhub sync` whenever skills/**
changes on main, publishing only changed skills to ClawHub
(https://clawhub.ai/heygen-com) under the heygen-com publisher and
auto-bumping the patch version. Unchanged skills are a no-op, so it is
safe to run on every push. Requires the CLAWHUB_TOKEN repo secret.
* ci: use Node 22 to match the CI fleet's LTS
Address review on #1835 (Miga): the rest of the CI fleet (ci.yml,
windows-render, player-perf, preview-regression, docs, catalog-previews)
pins setup-node to Node 22 LTS. Node 24 is current, not LTS, and could
introduce subtle differences. Align this workflow to 22.
