DeepSeek Harness Plugin: dsh-punycode

DeepSeek Harness (DSH) provides a plugin named `dsh-punycode` for Punycode conversion of Internationalized Domain Names (IDNs). The plugin is implemented in pure Node.js, has no network dependencies, and supports both encoding and decoding. Users can install it with the `dsh plugin add` command and invoke its tools directly within DSH sessions. This plugin provides foundational IDN processing capabilities for the DSH ecosystem and is suitable for agent development scenarios.