dsh-plugin-mobile-ui: Mobile UI Adaptation Plugin for DeepSeek Harness

`dsh-plugin-mobile-ui` is an official mobile adaptation plugin designed for DeepSeek Harness (DSH). It improves Web interfaces on mobile devices by injecting styles and components to address issues such as small controls, limited gesture support, and layout misalignment. The plugin provides features including drawer navigation, keyboard adaptation, landscape mode support, tool card replacement, and clipboard fallback. Installation requires downloading a tgz package and running the installation command, after which the service must be restarted for changes to take effect. Although it replaces some official tool cards, it significantly enhances mobile usability and is well suited for development and debugging in mobile browsers or WebViews.