dsh-v-explorer: The Official Right Sidebar Extension for DeepSeek Harness Web

`dsh-v-explorer` is an official extension for DeepSeek Harness Web, designed to enhance file browsing and bookmark management. It takes over the official file tree, providing lazy loading for directories, context menus, and file previews, and adds a bookmark view type that supports line-range reference excerpts. The plugin adopts a purely incremental mode and uses the ChangeFeed mechanism to enable automatic change-stream refreshing. It supports Markdown Reader Pro themes and JSON pretty-printing. Bookmark data is persisted locally and hidden from Git, with security validation in place, and tabs are synchronized in real time through SSE. By adjusting the viewport width via an interface, the plugin provides developers with a convenient tool for referencing and managing file snippets.