dsh-pause: A DeepSeek Harness Pre-Request Pause Plugin

The `dsh-pause` plugin for DeepSeek Harness is designed to address the challenge of intervening during consecutive agent requests. It pauses before the model is about to send a request while keeping the input box available. Users can press Enter or click a button to either continue seamlessly or type an interjection, without the model being aware of the intervention. The plugin is disabled by default, takes effect after a restart following installation, and is a community independently maintained pure plugin within the DSH ecosystem.