## Summary
- add a Docker-based macOS arm64 wheel build path so darwin wheels can be produced from Linux CI hosts
- wire macOS wheel builds into release publish workflows (`publish:main` and `publish:tag`) alongside existing Linux wheel builds
- mirror `crazymax/osxcross:latest` into `$CI_REGISTRY_IMAGE/third_party/osxcross:latest` and use that mirrored image in CI publish jobs
## Scope Notes
- this MR focuses on shipping reliable macOS wheel build support first
- temporary MR-only smoke-job wiring was removed after validation so the branch reflects final intended CI behavior
- broader cache optimization work is tracked separately in issue #43
## Test Plan
- run `mise run pre-commit`
- validate `.gitlab-ci.yml` with `uv run --with pyyaml python -c 'import yaml, pathlib; yaml.safe_load(pathlib.Path(".gitlab-ci.yml").read_text())'`