Might be worth looking into. I was not thinking of doing a massive job that met all required standards for a public building, more along the lines of running some 3/4" copper and adding 3-4 sprinkler heads with perhaps one over my gun safe. If it is a run of pipe with no other taps for hose, whatever, it would probably provide a decent degree of protection that might supress a fire or limit its effect. I believe it would be easy enough to put a pressure detector on the line to sound some kind of an alarm when the water started to flow.
A home bulit "safety system" that could be worthwhile that I would not rely on 100%.