#1)

* Move release flow to PR-based and add CODEOWNERS for branch protection

- Add .github/CODEOWNERS
- Cut a release branch in release.sh and open two PRs (sync to dev,
  release to main) instead of merging dev into main locally
- Move tag creation into a workflow that fires on push to main
- Skip auto_version_dev when Config.xcconfig was changed in this push,
  so merging the release sync-PR into dev does not double-bump

* Make workflow guards portable via fork check

Replace the hardcoded 'loopandlearn' owner check in workflows with a
fork check, so the workflows run on any non-fork repository (including
a test org) while still skipping on contributor forks.

* Allow skipping sister repo updates in release.sh

Set SKIP_SISTER_REPOS=1 to bypass the LoopFollow_Second / LoopFollow_Third
update_follower steps. Default behavior is unchanged: both sister repos
are updated as today and missing directories still cause a hard error,
so a forgotten clone in production fails fast.

* Revert "Allow skipping sister repo updates in release.sh"

This reverts commit c2792b8.