cardinal-wings and a code-quality pass

A remote management agent lands, dead code is removed, and state gets tests.

Two things land in 1.17:

  • cardinal-wings — a REST API daemon for managing containers remotely. It

runs as a systemd service and lets frontends (like a web panel) control

containers over HTTP with a Bearer token. A container-ID validation bug that

blocked start/stop/restart requests is fixed.

  • Code quality — an unused RCON package is deleted and the internal/state

package gains 12 unit tests for paths, JSON, and file checks.

This marks the point where cardinal grows beyond a single-host CLI and starts

to serve as a remote-controllable runtime.