DSH-Task-Notify: DeepSeek Harness Task Notification Plugin

`dsh-task-notify` is a DeepSeek Harness (DSH) client plugin developed by kaotusi, designed to address the issue that critical events during runtime are easily missed. The plugin pushes workflow events such as approval requests, reply waiting, background and subtask completions to the browser system notification center, and provides an in-app bell panel, Toast overlays, diagnostic status display, and one-click cleanup functionality. Core features include listening to multiple DSH events, invoking the Notification API to push notifications, and playing type-specific alert sounds. The system uses an in-host-process queue (with a maximum of 300 entries), and the client fetches new notifications by polling the `/api/taskNotify/pull` endpoint, deduplicates them via localStorage, and pushes at most 3 notifications per cycle. The plugin supports