Nice pictures! I do love how a poop board preserves the floor beneath for use for other things (I use the area to put my feed/water station).
Regarding your dog - are you open to the idea of running a strand of electric fencing around the outside of the coop/run --- a single strand about 4 inches off the ground that is about 4 inches out from the enclosure (using the long insulators is a good way to accomplish that) will teach the dog a good lesson about steering clear of the enclosure. Is the dog an outdoor dog? If not, then making sure outside time is under supervision where you are able to provide immediate correction as soon as he/she approaches the coop/run would be a good start.