GCFT CDN-172: Δ>0 Physical Floor Mapping — v* (Δ) Tracks cₛ (Δ), Acoustic Floor Partial, σ=16

CDN-172 maps the drag-peak velocity v* (Δ) across seven values of the spintessence stiffness parameter Δ ∈ 0, 0. 001, 0. 0025, 0. 00391, 0. 006, 0. 010, 0. 020 at σ=16, T=2000, using the CDN-166 linearised two-field equations with sponge boundary conditions (RK4, N=1024, dx=1). The window boundary is Δc = 1/σ² = 1/256 ≈ 0. 00391, at which the acoustic speed cₛ (Δ) = √ (Δ/ (Δ+4) ) equals the canonical bandwidth velocity 1/ (2σ) = 0. 03125. Key results: (1) v* (Δ) increases monotonically from 0. 036 at Δ=0 to 0. 081 at Δ=0. 020. (2) Above the window boundary, v* (Δ) tracks cₛ (Δ) with ratio v*/cₛ ∈ 1. 39, 1. 24, 1. 15 at Δ ∈ 0. 006, 0. 010, 0. 020. (3) At Δ=0. 020, ratio v*/cₛ = 1. 145 ≈ 1. 144 (the Δ=0 baseline ratio), consistent with the same Cherenkov-transient overshoot governing both the gapless and acoustic regimes at T=2000. (4) The ratio peaks at 1. 66 near Δc, a signature of mode competition at the threshold. The acoustic floor cₛ (Δ) = √ (Δ/ (Δ+4) ) is qualitatively confirmed as the physical lower bound for nucleation velocity above the window. CDN-173 (long-T runs at Δ>0) is pre-registered for quantitative confirmation. Lock code: CDN172DELTAFLOORMAPACOUSTICCSTRACKINGT2000SIGMA16PARTIAL Part of Project Aporion — General Coherence Field Theory (GCFT) theory audit sequence: CDN-168 floor refuted (CDN-170) → v* ~ 1/σ confirmed (CDN-171) → acoustic floor mapped (CDN-172).