SA_1 Anchor Tensor Skin Role Taxonomy

This paper formalizes the anchor–tensor–skin role taxonomy as a foundational classification for admissible description. Anchors fix non-violable constraints, tensors carry load-bearing structure, and skin provides expressive variability without affecting standing. The taxonomy is derived by exhaustion: any alternative role assignment either collapses into this scheme or violates admissibility and fails closed. The treatment is declarative and non-procedural, placing on record the minimal role structure required for standing preservation without introducing construction rules, design patterns, or operational guidance.