dsh-client-ui-pet: Adding a Q Desktop Pet Overlay to the DSH Web Interface

dsh-client-ui-pet is an MIT-licensed DSH Web GUI plugin maintained by qweqwe12382, designed to visually display session activity status through a chibi desktop pet overlay in the bottom-right corner of the page. The plugin maps the current session state to the character's expressions, actions, and dialogue bubbles, covering states such as idle, thinking, reading, editing, working, task completion, and error, each accompanied by rotating text and built-in sprite sheet frame animations. The plugin architecture is divided into host and browser components, with core functionality residing on the browser side, leveraging React and DSH runtime dependencies to inline images as base64, eliminating the need for static file routing. Users can install it via the `dsh plugin` command, and display preferences are stored in the browser's localStorage. This plugin is intended solely for display purposes.