* Introduce publish action with PyPI target detection via MIRRORS
* Resolve version from SemVer git tags on HEAD
* Support preview mode and non-interactive CI usage
* Build and upload artifacts using build + twine with token resolution
* Add CLI wiring (dispatch, command handler, parser)
* Add E2E publish help tests for pkgmgr and nix run
* Add integration tests for publish preview and mirror handling
* Add unit tests for git tag parsing, PyPI URL parsing, workflow preview, and CLI handler
* Clean up dispatch and parser structure while integrating publish
https://chatgpt.com/share/693f0f00-af68-800f-8846-193dca69bd2e