This work does not propose a new theory of gravity.Instead, it identifies the gravitational constant G as a structural normalization parameterthat must be fixed when a discrete microscopic phase-based dynamicsadmits a continuum mechanical limit. Within the JS–SH framework, spacetime is modeled using discrete rotational phase cellsand their adjacency couplings.By coarse-graining quadratic phase mismatch energies,we show that an isotropic long-range interaction necessarily emerges in the continuum limit,with the inverse-square (1/r²) form selected by symmetry and radial flux conservation. The remaining undetermined scale is shown to correspond uniquelyto the gravitational constant G, which occupies the normalization slotrequired for cross-scale mechanical consistency.No modification of Newtonian gravity or general relativity is assumed;existing gravitational formulations are recovered as the unique continuum closureof the discrete-to-continuum transition. This paper is part of the JS–SH Origin Series,which investigates the structural origins of fundamental constants,wave dynamics, and interaction laws from discrete phase geometry.