dsh-mdbox: A Markdown Editing Helper Plugin for the DeepSeek Harness Web Input Field

The DeepSeek Harness plugin `dsh-mdbox` is designed to optimize the list editing experience. It intercepts keypresses to support line continuation with `Shift+Enter`, automatic numbering incrementation, numbering reset when indenting with `Tab`, and merging into the outer list when outdenting with `Shift+Tab`. The plugin runs entirely in the browser, supports undo and Chinese input, and protects code blocks. The installation command is `dsh plugin --profile web add github:chi-hong22/dsh-mdbox`. It has no configuration options and does not access files or network data.