Init and Startup

Recommended order (see examples/pi/led-btn-ctrl.fnl and friends):

1. GpioCtrl.inst.reset^ — all pins input, peripherals off.
2. Assign named aliases: gpio27 o:.led!, pwm0 o:.pwmLed!, etc.
3. Configure each pin/periph, then true … .enabled!.
4. Create event sources (EventEscFn, EventTicker, …), .start^ / .eventEvery^ as needed.
5. Keep the instance in a global var so it stays alive.

: led-btn
  LedBtnCtrl.new^ dup
  LedBtnCtrl_inst !
  >ts
  t:.init^
  tdrop
;

Stop path: close event sources, GpioCtrl.inst.reset^, clear the instance var.

For headless / command-line launch (no TUI EventLoop yet), see Command Line Invocation and the runWithStart pattern in examples/events/ticker-timer-demo.fnl.