proactive-notify: DeepSeek Harness Proactive Notification Plugin

proactive-notify is a client plugin designed specifically for DeepSeek Harness (DSH), addressing the issue of users missing Agent task status updates when switching browser tabs. It leverages the browser-native Notification API to automatically send system-level notifications and play sound effects when the Agent encounters permission issues, completes a task, or is awaiting approval. The plugin is easy to install and launches alongside the DSH process; on first use, users need to enable notification permission in the bottom-right corner of the page. The installation command is `dsh plugin --profile web add "github:DemoJ/proactive-notify#main"`. Note that the browser tab must remain open, and the plugin requires a pnpm environment.