GCFT CDN-177: Measurement Noise Floor — v* Parabolic Method Sensitivity Limit, D8 Approximate Retained, σ=16

CDN-177 extends the CDN-176 convergence surface to θ∈{40,50,60}. Finding: the parabolic peak-finding method for v* breaks down when ε=v*/c_s−1 ≲ 0.02, where the peak force |F|_max drops to ~10⁻⁵ (the numerical noise floor). For Δ=0.060 the measured ε sequence is non-monotonic (0.020→0.044 at θ=30→40), physically impossible and confirming noise dominance. The CDN-176 simple-exponential convergence law ε(ξ,θ)≈0.83·ξ⁻⁰·⁸⁰·exp(−0.017·ξ⁰·⁴¹·θ) and D8 approximate award are retained. CDN-178 is pre-registered for a direct energy-flux measurement of v* to complete D8 at full precision. Lock code: CDN177_NOISE_FLOOR_REACHED_D8_APPROXIMATE_RETAINED