It’s hard to believe that there’s anyone in a large portion of the world — let alone in the Bay Area — entirely unaware of Harry Potter. Even those who haven’t read the children’s novels by J.K. Rowling or seen the movie versions have probably heard of the wizard school Hogwarts, the broomstick sport Quidditch, and quite possibly the four “houses” into which the students are sorted. For any as yet uninitiated and for diehard Potter fans alike, there’s a madcap summary coming to town.