From left: Hailey Truong and Michael Deni in "Into the Woods" at South Coast Repertory (Photo by Scott Smeltzer) Composer and lyricist Stephen Sondheim and James Lapine’s 1986 classic “Into the Woods” endures not only because it retells fairytales for adults, but because of Sondheim’s ingenious, harmonic music and clever, evocative lyrics. South Coast Repertory’s current production — excellently directed by Peter Rothstein with an invested and talented cast — does the musical