The reviewData variable is typed as `{ nodes: GitHubReview[] } | null`,
but the fallback value was `[]` (a plain array). When
`pullRequest.reviews` is null/undefined, `reviewData` becomes `[]`,
causing `reviewData.nodes` to return `undefined` instead of `[]`.
This leads to silent failures in downstream code that iterates over
`reviewData.nodes`, such as `filterReviewsToTriggerTime` and
`filterCommentsByActor`.
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
