dsh-visualization: DeepSeek Harness Visualization Rendering Plugin

`dsh-visualization` is a web plugin for DeepSeek Harness that renders Mermaid diagrams, data tables, Vega-Lite charts, and static SVG images in code blocks. Installation requires pnpm and a specific CLI version, and it supports multiple chart types, including kanban boards, quadrant charts, and C4 architecture diagrams. The plugin includes security isolation mechanisms, does not process HTML, SVG, or XML, and supports advanced interactive previews as well as filtering and pagination features.