v2.3.0

feat: factory reset in LCD settings menu

Scroll to the last item in Setup menu to see '>> FACTORY RESET <<'.
Press S to execute: clears all NV settings, shows confirmation,
beeps, and returns to home screen.

Accessible both from LCD (Setup menu) and serial ('factory reset').

v2.2.1

v2.2.1: Boot crash fix & stability

- Fix DABT boot crash (OP_MODE out-of-bounds array access)
- Add I2C bus timeout to prevent hangs
- Default MODE_THRESH for uninitialized EEPROM
- Remove non-functional disclaimer (firmware tested)
- Remove IAP flash profile references from all docs