dsh-plugin-installer-ui: DSH Plugin Manager

dsh-plugin-installer-ui is a visual plugin management plugin for DeepSeek Harness. It introduces a new “Settings → Plugins” tab to address the complexity of manual configuration. The plugin supports online installation and removal of plugins, and includes host-side proxying, client-side injection, and environment diagnostics. Users need to install pnpm and run the specified command to enable it; they can then perform operations by entering a package name or command. It aims to improve development efficiency and reduce errors.