TQNT-V5.8 — Derivation of Einstein equations from the V5 conformal metric

TQNT-V5.8 derives the Einstein field equations as the linearised, long-wavelength limit of the V5 conformal metric g_ij = (1 + κ_g |Ψ|²) δ_ij. Newton's constant G inherits from κ_g previously fixed to 3.13e-53 m at 0.05% in V5.7, so there is no free calibration in the gravitational sector. The emergent Einstein-Hilbert action is obtained at lowest order in (κ_g |Ψ|²) and the weak-field geodesic limit reproduces Newtonian gravity. This paper is the foundation document for the V5.9-V5.13 gravity and cosmology series. It complements the V5 monograph (10.5281/zenodo.19131538).