When a classic but outdated San Francisco building went on the market, the homeowners knew it was the ideal family home they'd been searching for. After an extensive remodel of the entire property from the studs on up, the kitchen now features a central island that doubles as kids' homework space and after-hours wine bar.  Removing a wall to the adjacent dining room created a space so bright and airy you'd never guess it was in the Richmond District. What fog?