Render the 4-gray watchface on TRMNL hardware

Load the GoodDisplay GDEY075T7 custom 4-gray waveform LUTs into the UC8179, clock
the ESP32-C3 up to 160 MHz so the software-float render finishes in seconds, and
pack each pixel's level into the two bit-planes. Add a calibration-bar diagnostic
and build the firmware ReleaseFast with the render core linked in.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Author: clebert