Migrate changelog management to `hark` (#2845)

* migrate to hark

* tweak issue template

* point the hark actions at master

* point at the renamed check-github-links action

* use the single hark/checks action in CI

* use the hark checks action and rename pr_link to pr_url

* record language and channel in versions.json metadata

* rename versions.json to releases.json

* regenerate changelogs; pad short versions

* add a minimum-runtime-version recipe

Committed-By-Agent: claude

* add print-version-info recipe

* swap from is_breaking to semver_level

* trigger CI for hark v1.0.0