Replacing the home button flex cable fixed the issue, I believe. I also restored the phone using iTunes. TouchID works now!!! I'm not a butter fingers wrecking ball when it comes to delicate electronics... woohoo!
I replaced the home button flex ribbon cable. All is well after restoring the phone. TouchID works. I felt the home button flex cable connector "snap" into place solidly. That was reassuring. The next reassuring event as not seeing the immediate "TouchID cannot be activated on this iPhone" message immediately after powering the phone on.