dsh-mobile-ui: DeepSeek Harness Reworked for the Palm

`dsh-mobile-ui` is a mobile adaptation plugin designed specifically for the DSH desktop version. By rewriting the interaction layer, it addresses issues in the original version where a narrow screen causes the sidebar and input box to overlap, and where tapping a session unexpectedly opens the keyboard. Core features include a full-screen drawer navigation, automatic drawer dismissal when switching sessions while keeping the keyboard state stable, a full-width Sheet for the settings page, and consistent circular touch buttons. The plugin also supports uploading local files, requires command-line installation to enable, and aims to deliver a mobile experience close to a native app.