dsh-smart-scenario-router: DeepSeek Harness Scenario-Based Model Routing Plugin

`dsh-smart-scenario-router` is a plugin for DeepSeek Harness, designed to address the manual model switching issue in multi-model environments. It automatically identifies the scenario based on user message content (such as code writing or everyday conversation), routes requests to the most suitable model, and automatically tries the next model if a request fails, reducing operational costs. The plugin supports prioritizing domestic models and features visual configuration and an automatic fallback mechanism. Installation requires meeting DSH version requirements, while configuration is simple and fully compatible with the existing authentication system.