1. PRs come with "the prompt". In openspec parlance this is a set of docs: a proposal, design, specs, task list.
2. I have a tiny skill to slice and dice PRs, so I can review each part of the system separately by rewriting commits in order of reviewal: specs/docs, production code, tests, evidence. I sometimes pull DB queries to a separate commit for focused review.
3. The evidence bit is built by another skill: go over all added spec scenarios and produce a markdown document with links to the code implementing the scenario and the tests proving the implementation works. Emacs helps me jump back and forth via those links and read the parts I'm interested in.
My next goal is to extend openspec schemas with custom workflow steps to make PRs land in my preferred review structure and contain the evidence report, so I don't have to build it.