Support other cli agents.

[mrcoleman]

It would be amazing if a user could support common cli tools like gemini-cli, opencode, codex and github-cli. It would probably mean you'd have to set a small and large model and cli in a config file.

Example config in ~/.config/johnny-bmad/config.json :

{
    "cli": "opencode",
    "models": {
          "small": "GLM 4.7 Flash",
          "large": "GLM 4.7"
    }
}