dsh-watch-maintain: Watch and Jewelry Maintenance Plan Generator

The `dsh-watch-maintain` plugin for DeepSeek Harness (DSH) is designed to address the need to embed specific business logic into agents, with a focus on generating maintenance plans for watches and jewelry. The plugin is maintained by developer istone, implemented in pure Node.js, runs fully locally, and does not rely on network requests. The installation command is `dsh plugin add github:uckkk/dsh-watch-maintain`; after installation, the `watch_maintain` tool can be invoked directly. Developers should be aware of environment dependencies and security risks, and it is recommended to install from trusted sources.