dsh-yzj: Yunzhijia x DeepSeek Harness Plugin

`guoxinshan/dsh-yzj` is the Yunzhijia integration plugin for DeepSeek Harness (DSH). It leverages the `yzj-cli` bridging system to provide 41 model-facing tools and a floating workspace panel. Core features include IM shell interactions compliant with Product Law v3.0 (with conversation-state and message-state switching), anchored @assistant replies in group chats, and support for sending to the assistant and replying in local threads. Installation requires running the relevant commands and restarting the GUI. Note that UI changes require rebuilding the bundle, and the Todo and AI Advancement features have been withdrawn.