dsh-jmcomic: Add JMComic search, download, and local reading to the DSH sidebar

`dsh-jmcomic` is an MIT-licensed DeepSeek Harness (DSH) plugin maintained by `lywusichen`, designed to integrate JMComic search, download, and local reading functions into the DSH sidebar without requiring switching to external applications. Featuring built-in `jmcomic` source code and a reader frontend, the plugin runs without additional PyPI package installations and requires a Node.js >= 22 environment. Core functions include searching and downloading comics by ID or title via sidebar buttons. After binding a local folder, users can browse a comic cover grid, manage local libraries (including chapter viewing), and read directly within the DSH window. The reader supports window dragging and resizing, position memory, resume reading (recording the last read chapter and page), page jumping, and card hover deletion.