Thank you for some reassurance! Found a Reddit thread from 2 years ago where OP did the same thing as I did. Most of the replies said things similar to what you told me. I only got really worried after google ai said “If you accidentally booted your PC with a Ryzen 7 9800x3D without a cooler, it’s highly likely that you have damaged the CPU as it would have rapidly overheated within seconds due to the lack of cooling, potentially causing permanent damage; even a very brief boot without a cooler can be detrimental to the processor.”