dsh-oauth-api: Third-party OAuth login plugin for DeepSeek Harness

dsh-oauth-api is a community plugin for DeepSeek Harness (DSH) designed to implement OAuth login integration for third-party models. It supports four providers—Grok/xAI, Codex/ChatGPT, Claude Code, and Kimi Code—and completes authentication via the Device code or PKCE flow. After installation, users initiate login through "Settings -> OAuth Login" in the Web interface, and the Token is stored locally in the `~/.dsh/oauth/` directory. The plugin injects corresponding `*-oauth` groups into the official model selector, allowing users to manually switch to models from specific providers for inference. Please note that successful login will not automatically change the default model.