GraphQL PullRequest reads the pull_request row: MERGED state, draft,
refs, head and base repositories, files, commits, reviews,
reviewDecision, mergeable and mergeStateStatus. repository.pullRequests,
is:pr search and the seven pull request mutations are served; comments,
labels and assignees accept PR_ ids. REST /repos/:o/:r/pulls covers
list, create, get (with diff and mailbox patch by Accept), edit,
commits, files, reviews and merge.
Pull requests reopen through PullRequestsService.reopenPullRequest.
Reviews get a numeric_id (0054). Commit authors resolve to accounts by
verified email. The web app serves a pull request at /pull/N, as GitHub
does, and redirects /pulls/N there.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>