There are some internal hub generator lights that are automatic, like this one B&M Eyc T Senso Plus Dyno Headlight . But for multiple lighting, I see a low-power bluetooth-like network standard where you pair the lights and if any one light is switched on or off they all follow in kind. This would also allow for a standalone button to be placed anywhere, and also for a photocell/motion sensor for automatic activation/deactivation