Resolve a pose's rotation transform, or null when the pose carries no
effective rotation. Non-null requires a nonzero rotationand all four
AABB fields (x, y, width, height) — the pivot is the unrotated AABB
center. Poses missing any AABB field (e.g. a bare polygon pose) or with
zero/absent rotation return null, so callers can treat null as "draw /
hit / clip in the local frame, no rotation step."
Resolve a pose's rotation transform, or
nullwhen the pose carries no effective rotation. Non-null requires a nonzerorotationand all four AABB fields (x,y,width,height) — the pivot is the unrotated AABB center. Poses missing any AABB field (e.g. a bare polygon pose) or with zero/absent rotation returnnull, so callers can treatnullas "draw / hit / clip in the local frame, no rotation step."