dsh-drag-path: Automatically Get Absolute Paths for Dragged Files/Folders

The `dsh-drag-path` plugin overcomes the limitation where DeepSeek Harness supports only image dragging. It intercepts drag-and-drop events and, on the Node side, resolves the actual absolute file system path based on file names and sizes, enabling batch drag-and-drop of files and folders. It uses a smart location strategy that prioritizes the workspace, is compatible with macOS and Windows, and works without configuration to insert file paths directly into the browser for Agent use.