Granted, the compute required is probably more expensive than github would offer for free, and IDK whether it'd be within budget for many open-source projects.
Also granted, something like this may be useful for human-sourced PRs as well, though perhaps post-submission so that maintainers can see and provide some manual assistance if desired. (And also granted, in some cases maybe maintainers would want to provide manual assistance to AI submissions, but I expect the initial triaging based on whether it's a human or AI would be what makes sense in most cases).
In my rules I tell it that try catches are completely banned unless I explicitly ask for one (an okay tradeoff, since usually my error boundaries are pretty wide and I know where I want them). I know the context length is getting too long when it starts ignore that.