Worried I damaged my fork fitting crown race I'm an idiot. I've been working on building up a Surly LHT frame and was all going fine until I got to fitting the crown race.

I couldn't get it to fit properly and instead of making a cup of tea and watching some how-to videos like I normally would, I fitted a metal pipe on the crown and a bit of PVC pipe above that and rested the forks on some carpet and smacked the pipe really hard with a metal bar. When I stopped I'd gone through the carpet and put a small (1mm) dent in the bottom of one of the dropouts (not deformed them). After that I went to my LBS and they milled the fork down a bit and fitted the race.

I've inspected the fork really carefully - no visible damage or bending. Is there any chance hitting it that hard could have damaged it somehow? I just don't know enough about steel as a material.
Nobody is going to be able to tell you 100% that its integrity hasn't been compromised from this. Steel can fatigue, brazed dropout joints are strong but not infinitely strong, etc. We all know it's a tough dropout and in all likelihood it's totally fine. But there's always a level of distant hypothetical risk that gets created when things like this happen to bike parts, and nobody can tell you just how distant.

Were a slightly more developed guess to be made, the first steps in getting there would be check dropout alignment (with dropout alignment tools), check the size and parallelism of the dropout slot with a caliper, and ideally check the fork alignment. The detail that's lost in time here, especially from an outside perspective, is exactly how hard it got hit.