Live and learn, but seems like your realtor should have offered some cautions for something like this when you where looking at houses.  You probably didn't meet your realtor in the van, but I expect the realtor had an idea of what you did for a living and I can't believe that at some point you didn't bring up the van and your requirement to have a place to park it.

Realtors can't be expected to know all the rules, laws and ordinances of specific towns or HOAs, but in my experience they are happy to look into stuff like this if they know you have specific requirements.