Adds Codex as a conversion/install target: each agent → `~/.codex/agents/<slug>.toml` with the three required Codex fields (name, description, developer_instructions).
Validated: all 184 agents generate valid, parseable TOML (incl. 21k-char agents with embedded code blocks) via the PR's TOML basic-string escaper. Matches OpenAI's documented custom-agent schema.
Thanks @yunuskilicdev.
Yunus Kılıç