fix(nesso): initialize LoRa frontend - #2840

Proposed Changes

Fix Arduino Nesso N1 onboard SX1262 LoRa initialization and reduce touch navigation repeat issues.

Nesso N1 LoRa wiring and RF frontend setup:

• SX1262 SPI shares the display SPI pins: SCK GPIO20, MOSI GPIO21, MISO GPIO22
• SX1262 CS: GPIO23
• SX1262 DIO1/IRQ: GPIO15
• SX1262 BUSY: GPIO19
• RF frontend control is on expander 0x43:
  • P5: LNA enable
  • P6: antenna switch
  • P7: LoRa enable/reset

This PR:

• adds a Nesso board-scoped LoRa frontend helper
• configures the 0x43 expander with read-modify-write register updates
• toggles the Nesso LoRa enable/reset path before RadioLib initializes SX1262
• configures the missing Nesso LORA_BUSY pin
• sets Nesso's default LoRa radio to SX1262
• sets Nesso's default LoRa frequency to 915000000.00
• adds a weak prepareBoardLoRaRadio() hook so other boards keep existing LoRa behavior
• makes Nesso touchscreen navigation edge-triggered so holding a touch region does not repeatedly spam navigation actions

Types of Changes

Bugfix / board support fix.

Verification

Repository state before opening this PR:

• GIT_EDITOR=true git pull --ff-only origin main — already up to date
• git diff --check — passed

Build validation with Homebrew-installed PlatformIO:

• pio run -e arduino-nesso-n1 — passed
• pio run -e m5stack-cplus2 — passed as a LoRa-path regression build

Hardware validation on a connected Arduino Nesso N1 / ESP32-C6:

• detected board on /dev/cu.usbmodem11201 (VID:PID 303A:1001)
• flashed patched firmware with Homebrew esptool
• esptool verified all flashed segment hashes
• Bruce booted after restoring the existing Nesso USE_TFT_eSPI_TOUCH input mode
• opening LoRa with SX1262 selected now enters the LoRa screen and shows USRN: BruceTest

I did not perform full LoRa packet TX/RX validation because a second LoRa peer was not available in this test setup.

Testing

Covered by PlatformIO builds:

• arduino-nesso-n1
• m5stack-cplus2

Covered by physical Nesso N1 testing:

• patched firmware flashed successfully
• board boots
• LoRa SX1262 path enters the LoRa UI instead of immediately failing initialization

Full LoRa packet TX/RX was not claimed here. This PR validates onboard SX1262 bring-up/initialization and UI entry.

Linked Issues

Refs #2816.
Refs #2813.

User-Facing Change

Fix Arduino Nesso N1 onboard SX1262 LoRa initialization and reduce repeated touchscreen navigation events.

Further Comments

The Nesso power/reboot button behavior from #2816 is not changed here. This PR focuses on the reproducible LoRa initialization failure and touchscreen repeat behavior.