dsh-ui-outline: Add round navigation rail to dsh web

`dsh-ui-outline` is a community-driven turn navigation plugin developed specifically for `dsh web`, aiming to address the challenge of quickly locating Prompts and Responses in long conversations. Maintained by iluluyu (MIT license, v0.0.2), the plugin adopts the official TurnNavigator design language, providing a sidebar navigation bar. It supports snapping to the nearest turn on click, drag-to-browse functionality, and the display of preview cards for each turn's content. Users can configure the sidebar position, preview material (e.g., frosted glass), and scale layout. Settings are persisted within the host's settings document, support both Chinese and English, and follow the system language. Installation requires a DSH version of at least 0.1.0-rc.7 and can be added via npm or GitHub command line. After installation, the service must be restarted and the page refreshed. The plugin runs with process permissions and relies on Re...