The idea of the mental model CAN be done by AI.
In my experience, if you get it to build a requirements doc first, then ask it to implement that while updating it as required (effectively it's mental state). you will get a pretty good output with decent 'debugging' ability.
This even works ok with the older 'dumber' models.
That only works when you have a comprehensive set of requirements available though. It works when you want to add a new screen/process (mostly) but good luck updating an existing one! (I haven't tried getting it to convert existing code to a requirements doc - anyone tried that?)
The trick is to split up the tasks into chunks.
Ask it to identify the blocks.
Then ask it to identify the connections.
Then ask it to produce the diagram.