In 1993, when Lois Lowry shocked adult and child sensibilities alike with her Newbery Medal-winning novel “The Giver,” J. K. Rowling had not yet begun scribbling magic words on the back of cafe napkins and Stephenie Meyer had just graduated from her (presumably vampire-free) high school. Suzanne Collins had just sold her first teleplays for the gentle, nonviolent world of children’s television, and “dystopia” was a 50-cent SAT word unlikely to trip off the average sixth-grade tongue.