dsh-openai-codex: An experimental plugin for DeepSeek Harness to access ChatGPT subscription-based Codex models.

`dsh-openai-codex` is an experimental, unofficial (out-of-tree) DeepSeek Harness plugin designed to independently integrate the pi-ai `openai-codex` model into DSH. It registers the model through DSH's exposed `ctx.llm` adapter interface and manages ChatGPT OAuth login using an independent credential file, thereby remaining completely isolated from DSH's built-in `llm-pi-ai` settings and without modifying installed DSH core packages. This plugin requires Node.js `^22.19.0 || >=24` and DSH `0.1.0-rc.7`. Users need to install the specified version via the `dsh plugin` command.