This release:

• fixes a bug in schan::schan-full? that made it incorrectly report a full condition when an schannel contained only one message.
• adds support for setting bus priorities on the RP2040 and RP2350 with the busctrl module.
• adds support for obtaining the number of free blocks with block::free-block-count@.
• adds a 6x12 font.
• adds support for ST7796S displays, including for PicoCalc emulation.
• adds support for LCD1602 with PCF8574 interface, as opposed to AiP31068L.