Bay seniors whose futuristic fantasies were stirred 60 years ago by GM Motorama’s self-driving cars and kitchens of tomorrow might want to check out the Metreon. Target has just installed a 3500 square foot all-acrylic “open” home there. It’s a demo of a connected “smart” house including digital controls for appliances, security, lighting designs, doorbells, even monitors that play soothing music as soon a baby cries. Free. Closed Thursdays. It is already happening. I know someone who has an app on their phone that that lets them call from anywhere and start the snow melting in the gutters on the roof of their mountain cabin.