VSCode-Style File Tree Sidebar Plugin for DSH Web Client: dsh-ymc-sidebar

The `dsh-ymc-sidebar` plugin provides a standalone right-side file tree sidebar for the DeepSeek Harness (DSH) Web Client, independent of the native `details` panel and compatible with blank sessions. Core features include a VS Code-style Activity Bar, width resizable by dragging, a virtualized and lazily loaded file manager, Git tracking with diffs, history, and branch management, and a browser view with local HTML rendering support. The plugin supports file watching and previewing through a persisted configuration file, aiming to deliver a VS Code-like development experience.