dsh-wsl-env: DeepSeek Harness WSL Environment Injection Plugin

`dsh-wsl-env` is a plugin for DeepSeek Harness designed to address issues where models confuse Windows and Linux paths and syntax in a WSL environment. It injects distribution information, path mappings (such as `C:\` to `/mnt/c`), filesystem considerations, and proxy configuration into the system prompt to ensure that the model executes tasks correctly. Users can install it via the command line and restart the service to apply the changes. It supports YAML-based custom configuration and is an important component of the `dsh-wsl-kit` suite.