One of the few strengths of PHP is that there doesn't have to be a "build process."
You don't even have to compile CSS and JS, really, but I guess people aren't comfortable with js or css which isn't machine generated. Fair enough - there are benefits to that, but as general practice, it's needless complexity.
I made it more obvious in the readme that you do not need build tools to run Hosty. Seems like that confused a lot of people.
I would just not use grunt. I understand it's not required to run it, but even as a build dependency, unless you already have Node installed and running, it's a lot of overhead for relatively little benefit, I think.
Granted, the amount of friction involved depends on personal preference, and whatever environment you're working in, but why require a package manager in another language (and, potentially, the language itself) when one exists for the language you're actually deploying in?
You don't minify your production js?