dsh-message-rail: DSH Web Left-Side Message Navigation Rail

dsh-message-rail is a DSH Web client plugin maintained by wx-yss, providing a Codex-style message navigation rail on the left side of the conversation view. Equal-distance tick marks indicate each user message, with hover previews displaying sequence numbers and timestamps, and click actions jumping to historical questions. The plugin establishes an index through an independent history API, supporting virtual scrolling and on-demand pagination loading. The installation command is `dsh plugin --profile web add dsh-message-rail`, requiring DSH 0.1.0-rc.6+ and Node.js 22+, licensed under MIT.