Choose groups and watched categories on signup

[Jonathan5]

@Benjamin_D

even if sign-up is not in the Available triggers list

I think it is now (at least, “first logged on” is close enough):

@joffreyjaffeux

Add user to group through custom field Recurring
First logged on Adds a user to a group based on a Custom User Field

Would the Automation plugin be able to set watch status per category based on custom fields too?