dsh-openui-studio: On-demand generation of OpenUI answers in DSH conversations

dsh-openui-studio adds an on-demand /openui command to normal conversations within DeepSeek Harness. It generates OpenUI Lang using the current session model, validates it through the official OpenUI chat library, and renders it using the official Renderer. Only turns with explicit /openui requests generate the interface, while normal messages remain unaffected. The answer supports layer-by-layer redrawing and replay, and buttons only fill the input box without auto-sending. The rendering configuration is located in render.js, and the model invocation configuration is in cordis.patch.yml. The plugin operates with the permissions of the current DSH process; please review the source code and license before installation.