After explicitly adding the missing CTA class, the JS change is now not mandatory for this to still be effective and without regressions (and is only kept as a nice-to-have for consistency) — if it would make it easier to review this fix without any MzpNotification tweaks I'm happy to spin them off to a separate PR for later.

Looks like this needs a rebase

@alexgibson Conflicts resolved via merge UI and CI passes (with no other conflict visible from my side currently). If you'd like a rebase instead LMK.

OR: Whenever you'd like to see the history edited out and cleaned up, just let me know, happy to fix up. I just usually keep the original mess before squashing to help reviewers follow the steps taken or changes backed out for some reason; so unless necessary, I don't overwrite the history just to appear "tidy", esp. in this case it's a bit more tiresome than what it would normally warrant;) — so if you don't plan on squashing and would like a better history instead I'm also happy to amend.