snoopfab

You should try rhasspy. It's open source. It respects your privacy by using offline services. Fully customizable (each service can be replaced by another) All the services are containerized for easy installation and is available for several architectures such as arm ( on a raspberry pi). There is even n Option to use Mozilla deepspeech tts service.

https://rhasspy.readthedocs.io/en/latest/

The jgraph Java toolkit and mxgraph JavaScript library used in draw.io both support automatic layout even for quite large networks. From the draw.io gui I've never used it but I would be surprised if the possibility does not exist.