grloper/dsh-claude-oauth: Claude OAuth Integration for DSH

`grloper/dsh-claude-oauth` is a plugin for DeepSeek Harness (DSH), designed to simplify the process of integrating the Claude model. It integrates OAuth authentication into the web interface, supporting one-click sign-in with Google/Gmail accounts, automatic token management, refresh mechanisms, and quota tracking. The plugin is IPv6-compatible and can sync credentials to the official Claude CLI, greatly reducing the configuration overhead of using Claude Pro/Max in DSH.