dsh-prompt-history: A Linux Shell-like Prompt History Plugin for the DSH Web Input Box

`dsh-prompt-history` is a client-side plugin for the DeepSeek Harness (DSH) web interface, designed to improve prompt-input efficiency. It introduces a Linux shell-like interaction model, supporting history navigation with arrow keys, reverse search with Ctrl+R, and direct paste via right-click. The plugin also provides a draggable conversation directory and cross-session history recall. Being purely UI-based, it is ready to use immediately after installation with a page refresh, making it ideal for developers who frequently reuse context or need efficient copy and paste of text.