dsh-poison-check: Pet Poison Detection Plugin

`dsh-poison-check` is a DeepSeek Harness (DSH) plugin maintained by developer uckkk, focusing on pet poisoning identification and emergency care. It is implemented in pure Node, requires no network requests, supports fast local responses, and can return appropriate emergency care instructions based on input parameters. Users can install it via terminal commands and invoke it directly within a DSH session. Since the plugin runs with the current process's permissions, users should review its source code and MIT license before use.