All of the current structure is now stained with preservative to prevent the wood from rotting (a problem with my previous shed) except the pressure-treated joists under the floor. I mounted the rails as well. Tomorrow the roof gets built!
One design thing I added was an extension to the roof structure on one side to accommodate the rack for the sliding gate motor otherwise the roof couldn’t fully close, since the gear on the motor would be a few inches inside the structure. This way the roof can entirely clear the building.