dsh-workspace-write-plus: Workspace Modification++ Permissions and Process Sandbox Allowlisting

`dsh-workspace-write-plus` is a plugin designed to resolve DeepSeek Harness (DSH) permission issues on Windows. It introduces a new "Workspace Modify++" permission, allowing processes such as Git Bash and PowerShell to bypass the Windows sandbox and fixing MSYS memory-mapping errors. The plugin supports a custom allowlist, ensuring that file operations remain within the workspace, making it suitable for users who need to use tools such as Git within defined security boundaries.