dsh-danmaku: DeepSeek Harness Trajectory Danmaku Plugin

`dsh-danmaku` is a visualization plugin developed for DeepSeek Harness (DSH) that displays trajectory data in real time as danmaku. It supports various events, including tool calls and assistant responses, and provides speed adjustment and edge-docking features. It can be enabled through runtime injection or persistent installation, with settings automatically saved to local storage.