X72-16: Continuous Layer-Cake Decomposition and Superlevel Distortion

Continuing from Round 15's weighted gauge-Hessian distortion ratio Ξ_Q=Q²H/(ν²D) (STOP-C19), this round instead performs a layer-cake decomposition of D and H using a continuous amplitude threshold λ∈(0,∞), without introducing dyadic shells. It proves that the global ratio Ξ_Q is a weighted average of the tail distortion at each continuous layer, so Q³ growth must force the existence of a dangerous continuous layer λ*; and derives the tail-surface evolution equation θ'=(a_Σ/d)(θ-σ) and the localized Hodge orthogonality identity E_M^u=D_M+H_M-2B_Q(λ), showing that localization itself comes at the cost of a boundary-flux tax. The route halts at STOP-C20 (continuous-layer distortion / boundary-flux gap): the boundary flux B_Q(λ) still has no unconditional control, and the baton passes to the next round to dissect the surface geometry of B_Q(λ) directly.