The $399 Apollo Neuro is the kind of wellness gadget that inspires skepticism. In a nutshell, it’s a wearable that claims to relieve stress through touch therapy. Apollo Neuro co-founder Dr. Dave Rabin describes it in a video as a “wearable hug for your nervous system” that uses silent vibrations to “rebalance” your fight-or-flight response. That, in turn, is supposed to make your body more resilient to stress by improving focus, increasing sleep quality, and raising your heart…