dsh-pet-wound: Pet Wound Treatment

The `dsh-pet-wound` plugin for DeepSeek Harness (DSH) is designed to provide first-aid care guidance for pet wounds. It is implemented in pure Node.js and runs without an internet connection. Developers can install it with the `dsh plugin add` command, then invoke the `pet_wound` tool in a session to obtain care recommendations. This plugin is suitable for lightweight scenarios where quick local access to pet first-aid knowledge is needed.