dsh-background: Configuring local background images in DeepSeek Harness Web

dsh-background is an MIT-licensed plugin for DeepSeek Harness Web designed to allow users to customize the web page background using local images while preserving the default theme and text readability. After installation, users can enter the absolute path of a local image in "Settings > General Settings > Appearance" and adjust the overlay intensity between 0% and 100% to optimize the display effect. The plugin supports common formats such as JPG and PNG (with a 25MB limit) and features real-time preview, automatic adaptation to light and dark themes, and configuration persistence. Since browsers cannot directly access local files, images are served by the host via the `/dsh-background/image` route. This plugin is suitable for scenarios requiring localized backgrounds without directly modifying the source code. It is recommended to review the source code for security before installation, and configuration files must be manually cleaned up after uninstallation.