dsh-chat-content-visibility-auto: DSH Chat List content-visibility:auto Optimization Plugin

`hongweifei/dsh-chat-content-visibility-auto` is a DSH plugin based on the MIT license, designed to optimize the performance of long-session chat lists on Web clients through pure CSS style overlay. By utilizing browser native `content-visibility: auto` and `contain-intrinsic-size` properties, this plugin skips the rendering, layout, and painting of off-screen message nodes, thereby reducing computational costs while keeping the DOM structure unchanged and without replacing any slots. To install, use the `dsh plugin` command to add the GitHub source, or manually configure junctions and package.json; the `dsh web` service must be restarted after installation.