For those of you who say you’d live in a closet just to benear the park, this might be your dream home. And this petite penthouse at103 East 84th St.isn’t justanycloset (though it does appear to beunder 200 square feet); not only is this unique co-op in a lovely full-service elevator building off Park Avenue, but the space that has been called “Manhattan’smost adorable penthouse” boasts a charming and sizeable private terrace to rival many a million-dollarproperty.