Pathfinding visualisation

It would be useful to see the places hearthlings can reach and places they cannot a cover overlay, green for accessible, red for inaccessible. that way you could see exactly what part of a construction is inaccessible, or why hearthings are refusing to move/complete a task/use a resource.

perhaps click on an individual hearthling and see everywhere he can go

Perhaps there should be options for debugging visualizations like this in the menu?