dsh-coffee-ratio: DeepSeek Harness Coffee-to-Water Ratio Calculator Plugin

The DeepSeek Harness (DSH) plugin `dsh-coffee-ratio` is a lightweight tool implemented in pure Node.js, focused on calculating coffee-to-water ratios without network dependencies. It registers the `coffee_ratio` tool, supporting precise calculation based on parameters and returning results along with empirical references. Users can install it via a terminal command and invoke it directly within a DSH session. The tool is suitable for integration in local computation scenarios; pay attention to plugin permissions and the license when using it.