fix: Wio Tracker LED on P1.01, move SimpleLed to board layer

Per the Wio Tracker L1 schematic, it has a green LED on P1.01.
Moved SimpleLed from driver/ to board layer (esp32s3.rs and
wio_tracker_l1.rs) since the impl needs HAL-specific Output types.
Removed driver/simple_led.rs — each board layer defines its own.
RAK WisBlock remains LedDriver=() (no user LED on the core module).

firmware/src/board/heltec_v3_uart.rs

@@ -10,7 +10,7 @@ use esp_hal::gpio::{Level, Output, OutputConfig};
 
 use super::esp32s3;
 use super::traits::{BoardParts, LoRaBoard};
-use crate::driver::simple_led::SimpleLed;
+use super::esp32s3::SimpleLed;
 use crate::hal::esp32s3 as mcu;
 
 pub use super::esp32s3::{
@@ -80,7 +80,7 @@ impl LoRaBoard for Board {
 
         // White LED on GPIO35
         let led_pin = Output::new(p.GPIO35, Level::Low, OutputConfig::default());
-        let led = Some(SimpleLed::new(led_pin));
+        let led = Some(SimpleLed(led_pin));
 
         BoardParts {
             radio,