So I don't buy the engineering angle, I also don't think LLMs will scale up to AGI as imagined by Asimov or any of the usual sci-fi tropes. There is something more fundamental missing, as in missing science, not missing engineering.
How long until that gets more reliable than a simple database? How long until it can execute code faster than a CPU running a program?
A lot of the stuff humans accomplish is through technology, not due to growing a bigger brain. Even something seemingly basic like a math equation benefits drastically from being written down with pen&paper instead of being juggled in the human brain itself (see Extended mind thesis). And when it comes to something like running a 3D engine, there is pretty much no hope of doing it with just your brain.
Maybe we will get AIs smart enough that they can write their own tools, but for that to happen, we still need the infrastructure that allows them writing the tools in the first place. The way they can access Python is a start, but there is still a lack of persistence that lets them keep their accomplishments for future runs, be it in the form of a digital notepad or dynamic updating of weights.
Doing it in a HTTP header is furthermore extremely lossly, files get copy around and that header ain't coming with them. It's not a practical place to put that info, especially when we have Exif inside the images themselves.
The proper way to handle this is mark authentic content and keeping a trail of how it was edited, since that's the rare thing you might to highlight in a sea of slop, https://contentauthenticity.org/ is trying to do that.