dsh-ulid: ULID Generation and Parsing Plugin

The DeepSeek Harness plugin `dsh-ulid` provides a pure Node.js implementation of ULID generation and parsing, with no dependence on external services. Users can install it using the `dsh plugin add` command and enable it in `package.json`. The plugin supports generating time-sortable unique identifiers, making it suitable for agent development scenarios, but users should be mindful of security risks related to local code execution.