dsh-chat-tidy: Tidy up layout and tables for DeepSeek Harness Web conversation page

dsh-chat-tidy is an MIT-licensed pure style plugin maintained by ChuanTianML, optimized for the layout of the DeepSeek Harness (DSH) Web chat page. By adjusting font, spacing, headings, lists, dividers, blockquotes, and table styles, it renders Markdown tables with the appearance of native DSH components, significantly improving the reading experience. The plugin does not modify DSH's Markdown rendering, themes, tool calls, reasoning, or session behavior, nor does it initiate network requests or store any data, ensuring the security of model outputs and host data. It supports built-in light/dark themes and is compatible with dsh-skin, but it is recommended to avoid using it simultaneously with similar layout plugins such as dsh-ux to prevent conflicts. Installation can be done via `dsh plugin -