'require' is not defined before using it
I don't believe we currently have code hinting for node-style require yet (Tern supports it but I don't think it works in Brackets for some reason - perhaps we just have to turn it on). Even if we turned that on, though, we would have to do some extra work to have it include the built-in node APIs (though it's also possible that Tern has that as well). I'm going to mark this "move to backlog" for this feature.
For now, you'd have to include the jslint options in a comment at the top of each file (you probably want /*jslint node: true */ to get all the standard node globals). In the next release we'll have a project settings file that you can use to set jslint options globally across an entire folder.
/*jslint node: true */