Shaurya-Ashu/C116 ? reverse-engineered prompt

Build me a tiny open source STM32 based microcontroller board called C116, with a USB C connector, a built in ToF distance sensor, a 2 by 2 RGB LED matrix, 3 GPIO pins, UART, and reset and boot buttons. I want it to be really small, around 1 cm by 1 cm, and feel like a complete little dev board that people can actually use and modify.

Please include the PCB design files, the firmware, and any simple build and production notes so someone can order the board and flash it. The board should support USB DFU style programming, using the boot and reset buttons to get into programming mode. Keep it fully open source and practical to manufacture, with clear documentation and visuals for how it works. If you need to check the latest docs for the chip, sensor, or USB C details, go ahead and look them up online.