So I ventured down to the garden floor to see what was going on with the doors. It reminds me of junior high school wood shop down there. I have the overwhelming urge to make a heart-shaped mirror shelf with a little dowel to hold a roll of adding machine paper.
First, they build the frame around the door and mark off where the hinges will go.
To make space for the hinges on the doors and the frames, they use a tool that carves out about 1/8th of an inch to allow for the thickness of the hinge.
However, since the little spinny thing in the tool makes rounded corners,
they have to chisel out a squared corner for my squared hinges.
And voila, the doors have hinges.
PS for the people who inquired about the door hardware on the moving wall: