variants/linux: meshcorectl, a dependency-free client for the console

[mmmorks]

Summary

A client for the PTY console, for the cases meshcore-cli -r does not cover. Its repeater mode is fine interactively, but in one-shot form it exits 0 whatever the daemon answered, waits a fixed 0.3 s and reads once, and cannot take commands from stdin, so a deploy script cannot tell set freq 868 from ERR: bad value or from a daemon that never read the line. It is also a pipx install that pulls in the BLE stack, on a host that may be a Pi Zero with nothing but python3.

meshcorectl is one file on the standard library:

• REPL with readline editing, history in ~/.meshcorectl_history, and Tab completion of the real command set (tables checked against the dispatch literals in CommonCLI.cpp and MyMesh.cpp; get and set have separate key pools).
• One-shot (meshcorectl set name foo) and piped (printf 'ver\nneighbors\n' | meshcorectl) forms.
• Exit 0 only if every command was actually run by the daemon. The echo is the proof: the daemon echoes a command byte by byte as it consumes it and only then replies, so reboot counts as run, and a later command in the same script that finds the console hung up fails with a message saying why.
• Finds the console the way the daemon publishes it (/run/meshcored/console, then $XDG_RUNTIME_DIR/meshcore/console, then /tmp/meshcore-<uid>/console); -s PATH or MESHCORED_CONSOLE overrides.

Its docstring records the firmware behaviours it cannot fix (clock sync needs a sender timestamp the console passes as 0; region load is multi-line).

What changed

• variants/linux/meshcorectl: the client.
• README: installed alongside meshcored in §1; §5 shows it next to meshcore-cli; ## The control CLI gains the three ways to drive it and the exit-code contract.

How it was tested

Exercised against a stand-in console (a Python PTY driven like the firmware loop) on macOS and in the arm64 container: one-shot, piped, --help, a missing path, a non-console path, a command with no reply text, and a piped script that continues past reboot (exit 1 with the reason). Not yet run against a real node.

Dependencies

Stacked on the PTY console hardening PR (pr/05-pty-console). Review the last commit only. Optional: the console works with meshcore-cli without this.

Shared code touched

None.