gc9a01.c and gc9a01.h were never committed to main despite ota_display.c
depending on their display_fill_rect/draw_string/draw_arc functions.
Also:
- CMakeLists.txt: add gc9a01.c to SRCS
- config.h: restore DISP_* GPIO defs (DC=8 CS=9 SCK=10 MOSI=11 RST=14 BL=2)
for Waveshare ESP32-S3-Touch-LCD-1.28
- ota_display.c: fix snprintf buffer too small (verline[32]→[48]) which
GCC 13.2.0 rejects as -Werror=format-truncation
Confirmed builds clean and boots on bd-66hx hardware (mbpi5 /dev/ttyACM0).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
