The Wyze Cam V2 offers the standard menu of home-security-camera features: high-def video, night vision, two-way audio, and continuous recording onto an SD card. But its $20 price is the fast-casual to the five-star dining of its three-figure competitors. The company’s trick: paper-thin costs and profit margins. The latest update makes the tag even nuttier: Wyze added an artificial intelligence that can differentiate between, say, falling leaves or buzzing bees and people, which minimizes false alarms.