dsh-water-care: Water Quality Maintenance Plugin

The DeepSeek Harness (DSH) plugin `dsh-water-care` is designed to provide agents with aquarium care solutions. Maintained by `uckkk`, it is a pure Node.js implementation that depends on `@deepseek-ai/cordis`. Users can install it with the command `dsh plugin add github:uckkk/dsh-water-care` and call the `water_care` tool to obtain water-quality maintenance recommendations. The plugin runs with the current process permissions, making it suitable for developers automating aquarium-related logic.