dsh-windows-notify: A Windows-Level System Notification Plugin

`dsh-windows-notify` is a Windows-native notification plugin developed for DeepSeek Harness (DSH). It uses the WinRT Toast API and PowerShell scripts to synchronize agent state changes, pending decision prompts, and task completion messages to the desktop in real time. Core features include pop-up notifications for agent status changes, decision reminders when user input is required, taskbar badge statistics, and customizable notification sounds. The plugin supports do-not-disturb periods, follows the system Do Not Disturb mode, and provides a web-based settings page. It currently supports only Windows 10/11, and DSH must be restarted after installation or upgrade.