dsh-desktop-notify: Desktop Notification Plugin for DeepSeek Harness

The DSH plugin dsh-desktop-notify addresses the need to manually watch the screen during agent development by leveraging native Windows notifications. It supports five types of event reminders, such as authorization requests, questions, and completions, and provides native notification banners, a full-screen fallback card, and a click-to-return-to-conversation feature. After installation, DSH requires a restart. Notification policies can be adjusted through a configuration file. The plugin is Windows-only and enables agents to run silently in the background.