GCFT CDN-161: The Stream Was Never Awake — A Matched-Baseline Simulation Audit of the Magellanic Stream Prediction

CDN-161 was built to close systematic S3 of CDN-160 (the ΛCDM trailing/leading baseline was a literature anchor, not a measurement in matched apertures) and instead exposed an internal inconsistency: the CDN-157 prediction of a +10–20% trailing-arm HI enhancement is not derivable from the surviving GCFT parameter set. A 2D test-particle stripping simulation with the canonical ingredients (NFW Milky Way, CDN-142 density screening f(ρ)=exp[−(ρ/ρ_crit)²], CDN-139 system-scaled coherence coupling κ_c = −0.5·GM_tot/v_typ = −7.9×10³ kpc² Gyr⁻¹, Kallivayalil et al. 2013 LMC proper motions) is run with the coherence term on and off, same seeds, same stripping, measured in the CDN-160 apertures. Results: at ρ_crit = 10³ M☉/kpc³ the stream is dynamically inert (enhancement 0.99); at ρ_crit = 10⁴ the T/L ratio is suppressed by ×0.44 — the opposite sign (robust at 0.46±0.01 across spray parameters); forcing CDN-157's assumed activation (f=0.75) destroys the leading arm (T/L~19); and the raw MW–M31 κ_c collapses the LMC orbit, violating CDN-139's own pre-registered infall constraint. Root cause: CDN-157 conflated the object-level compactness selector with spatial field activation — canonical screening places the f=0.5 surface at ≈260–390 kpc, beyond the stream. Consequences: CDN-157 is withdrawn as a falsifier; the CDN-160 pre-registered thresholds are retired (the measurement stands); and a new provisional tension emerges — if the suppression survives 3D hydro-grade simulation, ρ_crit ≈ 10⁴ predicts stream T/L ≈ 0.9, below the CDN-160 lower bound (1.35). Simulation script, results JSON, and figure included. By Nicky Hacquier (Aporion Dynamics) — part of the General Coherence Field Theory research chain, Project Aporion; follows CDN-160 (DOI 10.5281/zenodo.20618590).