Resolve PR Review Threads

Address the requested pull-request feedback completely. Preserve the user's authorization boundaries for commits, pushes, replies, and thread resolution.

1. Identify the Pull Request

Resolve the repository and PR from the user's input or the current branch. Use gh pr view for PR metadata, but do not use its comments field as the unresolved-review-thread source.

Fetch review threads through GitHub's GraphQL API because REST review comments do not expose thread resolution state: