And no, I wouldn't ever give it a year of changelog.md. I give it a short description of the current functionality, and a well-trimmed list of 'lessons-learned' (specific pitfalls/traps from previous work, so the AI doesn't have to repeat them)
If you think git logs are a good way to give context, try it and and see how it works! My instinct's that it won't work as well as a short readme, but I could be wrong. It's so easy to prototype these days, no reason to not give it a shot