I didn't mention this part, but while writing this I realized I could easily add a skill to hit the Forgejo PR API. There's no forgejo CLI like there is with GitHub sadly.
That seems like a problem an LLM could solve. ;) (Assuming Forgejo has a reasonable REST/whatever API.)
There is, but it's limited. For example Forgejo does not expose CI build logs via the API so it's hard to make Claude auto-fix a build issue.
I still need to find the time to get into the Forgejo code and add that endpoint.