nx_pose_skeleton.nx

nx_pose_skeleton.nx -- T2 POSE, the geometric skeleton analysis that turns keypoints (from nx_pose_keypoints) into a coarse POSTURE = the first rung of position/dance classification. NO CNN, NO trig, NO float: the body ORIENTATION comes from the spine vector (neck -> mid-hip) by comparing the dominant axis + its sign (image coords: y DOWN). Composes with nx_pose_keypoints' quarter-pixel keypoints; ready for real skeletons once the f32 pose CNN emits heatmaps. Honest first rung -- trained fine-grained position recognition is T3. license_tier: ORIGINAL