DeepSeek Harness Plugin: dsh-task-reminder

`dsh-task-reminder` is a plugin for DeepSeek Harness designed to address the lack of status awareness during long-running tasks. It notifies users via Windows system pop-ups and alert sounds when a task completes, is awaiting a response, or stops due to an error. Core features include three notification types (task completion, awaiting response, and error stop), click-to-return to the session, desktop window activation, four synthetic sounds, and support for custom local audio files. After installation, restart the host application and enable browser notification permissions; console commands are also provided for debugging.