Katja Grace’s apartment, in West Berkeley, is in an old machinist’s factory, with pitched roofs and windows at odd angles. It has terra-cotta floors and no central heating, which can create the impression that you’ve stepped out of the California sunshine and into a duskier place, somewhere long ago or far away. Yet there are also some quietly futuristic touches. High-capacity air purifiers thrumming in the corners. Nonperishables stacked in the pantry. A sleek white machine that does lab-qualit...