Nushell good first issues

The `nupm` tool is using a deprecated command `str downcase` which triggers a warning on first use. The issue suggests replacing `str downcase` with the recommended `str lowercase` command to resolve this deprecation warning.

Debug a Nushell webserver library where `nc` and `cat` processes sometimes persist after the script exits. The issue is infrequent and may be related to resource constraints or a Nushell bug. The task involves investigating process management within the Nushell script, potentially examining the use of `try` blocks and resource limitations as contributing factors.