Adds `velxio-ssd1306-i2c-4pin`, a native 4-pin SSD1306 OLED module
(GND/VCC/SCL/SDA) — the cheap 0.96" I2C board most beginners actually have,
matching Wokwi's board-ssd1306. The 8-pin `wokwi-ssd1306` breakout stays; this
is the distinct 4-pin part (issue #215). Same SSD1306Core render pipeline
(imageData/redraw) so the display paints identically; I2C-only, address via the
i2cAddress property (default 0x3C). Styled after the existing 8-pin element
(blue PCB, dark screen, corner holes, star).
Ships four "SSD1306 OLED (4-pin I2C)" gallery examples wiring it over I2C on
Arduino Uno (A4/A5), ESP32 (21/22), Raspberry Pi Pico (GP4/GP5) and STM32 Blue
Pill (PB7/PB6).