Releasing

The version is single-sourced from shuttle/__init__.py (__version__). pyproject.toml reads it, so a tag, the built wheel and shuttle version cannot disagree.

1. Move the ## [Unreleased] entries in CHANGELOG.md under a new ## [X.Y.Z] - YYYY-MM-DD heading.
2. Set __version__ = "X.Y.Z" in the same PR. CI refuses a version that has no matching changelog section (scripts/check-changelog.py).
3. Merge, then tag the merge commit vX.Y.Z and push the tag.

The release workflow then:

• refuses a tag that disagrees with __version__;
• runs the suite;
• builds the wheel and sdist, installs the wheel clean and checks it reports the tagged version;
• publishes the release with checksums.txt, using that version's changelog section as the release notes.

After a release

• The unattended actuator on the fleet host installs the new release on its next tick (checksum-verified, command-tested, atomically promoted).
• caboodle installs only the version its member manifest pins. Move the pin with caboodle bump-member members/shuttle.toml in a caboodle PR.