Cardputer Buddy app bundle
The buddy/ directory in the local build-with-claude clone is the MicroPython payload that m5-onboard installs onto /flash/. Work inside that clone.
Device layout
main.py scans /flash/apps/ at boot and lists every .py as a menu entry. Drop a file into buddy/device/apps/, push it, and it appears on next boot.
Adding an app
Crib from buddy/device/apps/hello_cardputer.py — smallest example of keyboard polling, font, and exit conventions. Then push without re-flashing:
<PORT> is whatever detect.py reported last run (e.g. /dev/cu.usbmodem1101, /dev/ttyACM0, COM3).

