Hi, grumpymutt. Welcome to the Grumble!
First, will share a few thoughts on how it might have happened, for if you plan to buy more such art in the future. From what you've shown, I'm guessing that the painting was one on a thinner fabric than the usual heavy cotton canvas. We get them in sometimes, usually from folks who bought them while traveling abroad, and the fabric is basically like bedsheet material. (It's also common for the artist to have left too little edge fabric for proper stretching, which is a whole other chat.) Even when a framer is very careful, there's the risk of this thin fabric tearing, or the staples breaking through. It also looks like older fabric, and the way the painting cracked makes me wonder if it's been around for awhile, too. That's always a risk with older paintings. I suppose, too, that an artist could use old fabric for a new painting. Whatever the case, it sure is a bummer. It's possible the cracking was caused from the paint being so old and brittle that it even gentle stretching was too much. It's also possible that, due to the nature of the fabric, the framer pulled very tightly, hoping to somehow get it flat. Your options were likely, to either have this, or a floppy canvas. Thanks for taking time to read all that, and if you already knew it, please forgive the redundance.
As to your question, there are different levels of treatment available. For this one, your idea of a light coating might be helpful (but let the experts here chime in on that). For pieces of high value, whether sentimental or monetary, painting conservators have more options. When paint cracks, it might only be in those places, but it could also be that the paint is separated from the canvas around the cracks, or in other areas, that one can't see. If the flakes are big, they sometimes inject fish blue through the back of the fabric, then attach the flakes from the front. And they have other wizardly tricks, as well. But, unless this piece is more valuable than I'm guessing, you'll likely be happy with a simpler fix.