dsh-tea-brew: Water Temperature and Steeping Time for Brewing Tea

The DSH plugin `dsh-tea-brew` is a pure Node.js implementation of a tea-brewing utility maintained by uckkk, with no network dependencies. It provides the `tea_brew` function, which precisely calculates the required water temperature and time based on the input tea parameters. Users can install it with the `dsh plugin add github:uckkk/dsh-tea-brew` command, and after installation, call the registered tool in a conversation to quickly obtain tea-brewing recommendations.