At the height of the covid-19 pandemic, many wearable companies rushed to see if their devices could detect early signs of the disease. Now, four years later, Oura is officially launching a feature that can flag when you may be coming down with a respiratory illness.Technically, Symptom Radar isn’t diagnostic in nature — though its development does have roots in Oura’s illness prediction research during the pandemic. It can’t tell you if you’re catching a cold or the flu versus covid-19. Instead...