Custom shutdown animation
ANSWER:

So this took me some troubleshooting to fix.

During this process I was using the Linux Archive Manager GUI to work with my animation files.  This was my mistake.

At one point, as a test, I deleted folder part0 from the archive, and then added it right back in and pushed it back to the phone.

Black screen.  This was my "A-Ha!" moment.

My archive manager was automatically compressing everything I added to it.  Thus, after adding part0 back into the archive I noticed the compression ratio changed from 0.99 to 1.34...

Easy fix:  I created an uncompressed new bootanimation.zip file 

zip -r -0 bootanimation.zip part0 part1 desc.txt

worked flawlessly. Custom animations now work.