Apply the Xiaoyao Skin to the DeepSeek Harness web interface using dsh-xiaoyao-skins

dsh-xiaoyao-skins is a collection of DeepSeek Harness Web skins maintained by 147228: six installable and uninstallable presentation layer plugins, plus the xiaoyao-skin installer and community scaffolding. It only modifies the webpage appearance without replacing sessions, models, tools or sandboxes. The directory installation command is `dsh plugin add github:147228/dsh-xiaoyao-skins`; use `xiaoyao-skin use` to switch skins daily. The code is licensed under MIT, derivative builds are supported under BSD-3-Clause, Xiaoyao's artwork is licensed under CC BY-NC 4.0, and the community directory is not an official DeepSeek store.