dsh-web-shell: Add a right-docked Web terminal to DeepSeek Harness

# Introduction When developing with `dsh web`, it is often necessary to execute a few commands on the fly directly in the browser. Two common approaches exist: switching to a separate terminal window, or using an overlay terminal that obscures the session content. The former requires constant context switching, while the latter obscures the ongoing conversation. The dsh-web-shell introduced below adopts a third approach: it docks the terminal on the right side of the window, automatically making room for the main chat area. This ensures the terminal and session content remain visible simultaneously, and the collapsible panel does not interrupt the session. # What is dsh-web-shell? dsh-web-shell is a right-docked Web Shell plugin for DeepSeek Harness, maintained by JesmonX. It is released under the MIT license, and the current version on npm is 0.1.