- TOUCH_SDA=17 SCL=18 RST=38 per Waveshare schematic
- GPIO 8/9 conflict with LCD_B0/B3 was blanking the display
- Banner uses BOARD_NAME macro instead of hard-coded E32R35T
- TFT_eSPI #error wrapped in USE_TFT_ESPI guard
- RGB test fills on separate lines so they actually execute
Required for uint16_t, Serial, millis() etc. when compiling
outside the .ino (Arduino IDE auto-includes Arduino.h for .ino
files but not for standalone .cpp files).