The lights dim, and for the next hour and 45 minutes, children watch as Charlotte the spider and her barnyard friends save Wilbur the pig. For many of these Philadelphia-area students, the Arden Theatre Company’s production of Charlotte’s Web is their first live theater experience. As participants in Arden for All (AFA), the theater’s arts education program, they’ve read the classic story, but now they’re seeing it come to life onstage.