dsh-wsl-download: Managing Windows Downloads in WSL

`dsh-wsl-download` is a v0.2.0 plugin for DeepSeek Harness (DSH) that simplifies file interactions between WSL and the Windows Downloads folder. It provides the `win_download` tool, supporting file listing, file copying, and model path suggestions. It does not initiate download tasks and only handles file management, making it suitable for using Windows-downloaded models or datasets in WSL.