dsh-file-panel-left: DSH Web Pure File Workspace Sidebar

`dsh-file-panel-left` is a lightweight file workbench plugin for DSH Web that integrates file management, code editing, and preview capabilities. It uses a left-tree/right-content layout and supports syntax highlighting, multi-format viewers, and code references. The plugin provides core features such as lazy-loaded trees, automatic edit saving, and JSON formatting, while maintaining state through session isolation. It is easy to install and suitable for improving the efficiency of file operations.