dsh-jwt-uckkk: JWT Decoding and Expiration Check

DSH Harness provides the `dsh-jwt-uckkk` plugin for quickly decoding and inspecting externally provided JWT tokens. Implemented in Node.js, the plugin is intended only for viewing the header, payload, and expiration, and does not perform signature validation, making it suitable for debugging scenarios. Users need to install the plugin via the CLI and enable it in the Profile configuration, after which they can call the `jwt_decode` method to parse the token. Note that the plugin runs with the current process’s permissions. Please review its source code and license before use, and use it only for data inspection; do not directly trust token integrity in production environments.