The Forgejo Runner v2 backend plugin is now hosted at github.com/alexisbchz/hyperfleet-forgejo-plugin so it can be released and versioned independently of the daemon. Removes forgejo-plugin/ from this repo, drops the `make plugin` target, and points the README at the new home. The hyperfleet daemon's REST API and in-guest initd protocol are unchanged — anyone is free to write a different backend plugin, runner, or higher-level orchestrator on top of them.