Apple doesn’t need its own TV set. But it should make a low-cost TV streaming stick to bring its content, apps and smart home features to more households. Also: Siri will be revamped for the modern AI era; Amazon beats Apple to new smart home displays; and Oura and Dexcom team up in a bid to make glucose tracking mainstream.Last week in Power On: Apple’s Tim Cook has ways to cope with Trump’s looming tariffs....