Puck strolls across the stage, confidently hits her mark, then scampers off for backstage accolades and belly rubs. Yes, belly rubs. The three-year-old terrier mix is one of the four-legged stars of Muncie Civic Theatre’s production of “A Midsummer Night’s Dream,” opening this weekend at Minnetrista’s Oakhurst Gardens. Amy Leffingwell, who plays Starveling in the…