Feature Request: Support for Overlay Configuration via MQTT

[Doppelherz]

It would be fantastic to have support for overlay configuration through MQTT.

Use Case:
This would allow integration with Home Assistant scripts, making it possible to trigger actions using voice commands with HomeKit. For example, I could say:
"Siri, set Toniebox max speaker level to 25%"
and then simply press the Toniebox ear to apply the configuration—without needing to open the Teddycloud interface beforehand.