dsh-theme-plugin: DSH Web GUI Theme Presets and Light/Dark Mode Customization

The dsh-theme-plugin is a theme plugin for the DeepSeek Harness Web GUI, offering 5 preset themes along with Light/Dark mode customization capabilities. Users can adjust accent, background, foreground, font, sidebar transparency, and contrast in real time, with changes applied instantly via the official API without requiring a page refresh. Selections are saved in localStorage and persist after refreshing. The plugin injects styles through the official seam without modifying source files, deriving over 70 semantic tokens based on background and other properties. It provides both a GUI settings interface and a YAML configuration method, with the GUI taking priority over the configuration file. Installation requires Node.js 22.19+; users can execute the specified command to add the plugin and restart the web service to enable it. It is suitable for users who wish to personalize the DSH interface to enhance their reading experience; note that color controls are not available under the stock preset.