ST. JOHNSVILLE — Phoebe Sitterly, 60, has spent many a time with friends and a sweet, creamy cup of coffee at the Bridge Street Diner in St. Johnsville. Minus an early snow squall in mid-November, it was an ordinary scene at 10 Bridge St. But the retired teacher's plate has changed of late. "I don't come every day," Sitterly said while seated at the village establishment. "I think it's important, though, that when you are in politics that you're visible in the community and willing to talk to people." Sitterly has been town supervisor for roughly three weeks amid an…