Implements IDekiGPIO with three jobs: drive a pin, read a pin, and count a pin’s edges by interrupt, so a device that pulses faster than a game polls (a trackball, a rotary encoder) loses no steps. The platform package supplies the pins; on ESP32 that is deki-esp32-integration.
GpioPinSetup is a boot step that drives one pin high or low, with an optional wait afterwards: the rail that powers a display, or the chip select of a device sharing its bus. Board packages use it to bring their hardware up in order.