feat(boards): add LilyGO TTGO T4 v1.3 support

[hadifarnoud]

Summary

Adds a board target for the LilyGO TTGO T4 v1.3 — ESP32-WROVER with a 2.4″ ILI9341 320×240 SPI display, microSD slot and three front buttons. There was no existing T4 target (the closest, lilygo-t-display-ttgo, is a different ST7789 135×240 device).

✅ Tested on real hardware

This board target was flashed to and verified on a physical LilyGO TTGO T4 v1.3:

• Boots straight into the Bruce menu (replacing the factory demo firmware).
• Display renders full-screen in landscape with the correct Bruce theme colors (dark background, purple/pink accents).
• All three front buttons navigate the menu.
• Flashed via esptool --chip esp32 write_flash -z 0x0 Bruce-lilygo-t4.bin after a full erase_flash.

The two follow-up commits (color inversion + rotation) are the corrections found during this on-device bring-up.

What's included

• boards/lilygo-t4/pins_arduino.h — full pin map, ILI9341, landscape ROTATION 1
• boards/lilygo-t4/interface.cpp — 3-button navigation (top = previous, middle = select / escape on double-click or hold, bottom = next), backlight PWM, deep-sleep power-off with wake on the middle button
• boards/lilygo-t4/lilygo-t4.ini — PlatformIO env (4 MB, custom_4Mb_full.csv)
• boards/lilygo-t4/connections.md — pinout documentation
• boards/_boards_json/lilygo-t4.json — ESP32 board definition (-DLILYGO_T4)
• boards/pinouts/pins_arduino.h — dispatcher branch for LILYGO_T4
• Registered lilygo-t4 in platformio.ini, PR_All_envs.yml, buil_parallel.yml, manual_build_sel_env.yml and docker/run_all_envs.sh

One small core change

src/core/config.h gains an overridable default:

#ifndef DEFAULT_COLOR_INVERTED
#define DEFAULT_COLOR_INVERTED 1
#endif
...
int colorInverted = DEFAULT_COLOR_INVERTED;

begin_tft() applies tft.invertDisplay(bruceConfig.colorInverted) at runtime, so a compile-time TFT setup alone can't fix a panel that shouldn't be inverted. The default stays 1 for every existing board; this T4 panel sets -DDEFAULT_COLOR_INVERTED=0 in its .ini. Without it the T4 renders with a white background and green accents.

Pin map

Function	Pins
TFT (ILI9341, VSPI)	MOSI 23, MISO 12, SCLK 18, CS 27, DC 32, RST 5, BL 4 (active HIGH), 240×320, ROTATION 1
SD card (HSPI)	CS 13, SCK 14, MISO 2, MOSI 15
Buttons (active LOW)	38, 37, 39
I2C (Grove)	SDA 21, SCL 22

The three buttons sit on ESP32 input-only GPIOs (37/38/39), which cannot use internal pull-ups — they rely on the board's external pull-ups and are read as active LOW.

Pins were cross-checked against the official LilyGO TTGO-T4-DEMO and the TFT_eSPI Setup22_TTGO_T4_v1.3 profile.

Build

pio run -e lilygo-t4 builds clean — Flash 85.3%, RAM 30.5%, produces Bruce-lilygo-t4.bin.

[hadifarnoud]

Confirmed working on a physical LilyGO TTGO T4 v1.3: flashed over USB, boots into the Bruce menu full-screen in landscape with correct theme colors, and all three front buttons navigate. The color-inversion default and the rotation fix were both verified on the device.