FixNEW V4: Point 1 - Fourth Law Conservation Derived - DESI DR3 falsifiable prediction z_c=0.4215±0.02

Point 1 - Fourth Law Conservation Derived We derive the Fourth Law of vacuum energy conservation: S_AV = ∫ d^4x √-g (V_AV - V_EX) (1) ∇_μ T^μ0 =0 => d/dt[V_AV+V_EX] = -H(z) B_AV(z) (5) B_AV(z_c)=0, z_c=0.4215 => d/dt[V_AV+V_EX]|_{z_c}=0 (6) Integration yields Fourth Law: V_AV + V_EX = const (7) V_AV(z) = 1/3 B_AV(z) H0/H(z) (8) This is falsifiable by DESI DR3: z_c = 0.4215 ± 0.02 (10) If no crossing in [0.40,0.44], model ruled out at 3σ (11) Previous values: V_EX,0 = +1.65e-11 J/m3, B_EX,SS = -5.16e-11 J/m3 File: FixNEW_V4_FINAL_PDF.pdf contains 11 equations + derivation. V3 DOI: 10.5281/zenodo.23118905