ruby_llm-providers-codex

https://github.com/madbomber/ruby_llm-providers-codex

Adds a codex provider to RubyLLM. Prompts are written to the Codex CLI's stdin in non-interactive mode and its JSON events are read back from stdout, so the agent (with its own tools, config and resumable threads) can be used wherever RubyLLM expects a model, e.g. `--model codex/default` in aia.