dsh-butter-convert: A Local Butter Unit Conversion Plugin

`uckkk/dsh-butter-convert` is a pure Node.js plugin based on DeepSeek Harness (DSH), focused on butter unit conversion. It can be executed locally without an internet connection and provides accurate conversion results. Users can install it using the `dsh plugin add` command and then use it directly by invoking it in a session after installation. The plugin depends on specific versions of environment libraries, runs with the permissions of the current process, and the project is open-sourced under the MIT license.