Adds a LEDManager class (src/helpers/ui/LEDManager.h) that centralizes
all LED control into one component with begin()/loop() lifecycle and
per-pin active-HIGH/LOW polarity support.
LED settings are exposed as custom vars (led.status, led.activity)
accessible via companion radio binary protocol, CLI set/get commands,
and the SensorManager settings interface.
Status LED modes: off, boot-30s, slow blink (200ms/4s), always on.
Activity LED modes: off, BLE only, LoRa TX only, BLE + LoRa TX.
Integrated into 23 board variants, replacing scattered hardcoded
digitalWrite calls in onBeforeTransmit/onAfterTransmit/powerOff.
The RAK13302 1W module uses a Skyworks SKY66122-11 front-end module with
three digital control pins (CSD, CTX, CPS) that must be actively driven
by the host MCU. The previous code only managed CTX (GPIO 31) — toggling
it for TX/RX — but never initialized CSD (GPIO 24) or CPS (GPIO 21),
leaving them floating with no pull-up/pull-down resistors on the PCB.
With floating CSD and CPS, the SKY66122 was in an undefined operating
mode:
- The 30 dB TX PA may not have been reliably engaging
- The 16 dB RX LNA was never reliably active, degrading receive
sensitivity
