botscent-check
botscent-check/<version> is the user agent of npx botscent check <url>, a command that a site's own developers run to confirm that their Botscent installation works.
Each run sends two requests to the URL it was given, one with this user agent and one with an empty one, and opens the page once in a browser on the developer's machine. It follows no links, does not crawl, and sends nothing anywhere else.
If you see it in your logs, someone ran the command against that URL. It declares itself so that Botscent reports it as an agent.