dsh-codex-auth-bridge: Reusing Codex CLI's ChatGPT OAuth Login

The `dsh-codex-auth-bridge` plugin provided by DeepSeek Harness (DSH) aims to address the inconvenience of developers maintaining separate API keys for DSH and Codex CLI, enabling reuse of the OAuth login state. Delivered as a Host Cordis bundle, its key features include reading Codex’s `auth.json`, keeping tokens fresh through native implementation, automatically synchronizing access tokens to the DSH credential service, and configuring model routing for `openai-codex`. After installation, DSH can call ChatGPT models directly via the `dsh-llm-pi-ai` adapter, and the plugin supports automatic refresh of expired tokens, concurrency protection, and local security.