Since switching from SVN to Git, we lost the ability to enforce our coding standards through a pre-commit
hook on the subversion server.
With Git, you only
I don't think there's a technical solution here but if you really want to bother people, then integrate phpcs
into your CI setup and start opening tickets for it in your issue manager. ;-)
I don't think that's the best idea though because it's really not a technical problem. Your issue is not a pre- or post-commit hook, but that people don't do it and you think you have to force them.
All in all, I understand the importance of a coding standard and I enforce one as well, but there's a social component (or aspect) to it.
It sounds like the people working with you either don't know any better (yet) or are un-willing to learn. So, in case they don't know any better you have to work with them and teach them to adhere to your requirements. That includes teaching them why conventions are important and in the end they need to understand that a feature is not done until everything is green.
Maybe that requires that project management (I gather that's you) breaks down an issue into multiple tasks until they get it:
phpcs
(In no specific order. ;-))
If they're unwilling to learn you can always take more drastic measure. Like, I'd start off slowly and do a weekly performance review (1-on-1 situation) and reiterate why they don't do it. If that doesn't help -- I guess you catch my drift.