DeepSeek Harness Plugin: dsh-llm-openai-codex

DeepSeek Harness (DSH) introduces the new `dsh-llm-openai-codex` plugin, designed to resolve authentication failures when calling OpenAI Codex locally due to missing API keys. It reuses pi-ai's general request mechanism and supports authentication via OAuth tokens, requiring a ChatGPT subscription, eliminating the need to configure an API key. The plugin supports automatic token refresh and model discovery, and provides a Web login card, supporting either PKCE or device code, for identity verification. After installation, it must be enabled in the configuration file, and models must be used in the `openai-codex/<model>` format. Community-maintained, the plugin extends DSH's local inference capabilities.