dsh-grok-build-auth-bridge: Reuse Grok Build CLI Subscription Login

The DeepSeek Harness (DSH) plugin is designed to streamline integration with Grok Build by reusing the official CLI's security mechanisms, delegating token refresh to the system, and synchronizing only access tokens. The plugin hosts a Cordis bundle, automatically handles the OAuth flow, requires no manual token maintenance, and supports provisioning routes for Grok Build subscription proxies. Installation requires environment prerequisites such as Node.js 22.19+, with attention to Unix permission settings and potential environment variable interference. Released under the MIT License, the plugin achieves a balance between convenience and security.