Parameter-Free Resolution of the Hubble and $S_8$ Tensions via String-Emergent Topological Volume Generation

The standard cosmological model ($\\Lambda$CDM) is increasingly challenged by the persistent and conflicting Hubble ($H_0$) and large-scale structure growth ($S_8$) tensions. In this Letter, we entirely bypass phenomenological curve-fitting by deploying the macroscopic low-energy limit of the String Field Theory Emergent Framework (SFT-EF). We analytically demonstrate that macroscopic cosmic expansion behaves as a thermodynamic consequence of a structurally rigid Face-Centered Cubic (FCC) vacuum lattice condensate. While safely guarding local General Relativity via an active non-linear Vainshtein kinetic screening mechanism, we strictly anchor the macroscopic effective action to fundamental \\textit{ab initio} string invariants---specifically the transverse bosonic worldsheet scaling ($\\gamma_{\\text{th}} = 1/24$) and the continuous lattice site percolation threshold ($p_c \\approx 0.1891$). This exact geometric grounding dictates a completely parameter-free predictive cosmological signature. We analytically extract a late-time phantom dark energy attractor dynamically bounded at $w_0 = -1.08$. Crucially, this topological volume generation is structurally coupled to an exact, non-conservative phase-space drag modifying the Euler perturbation equations, physically suppressing macroscopic linear structure growth by exactly $\\Delta f\\sigma_8 \\approx -1.7151\\%$ at the present epoch. Comprehensive Bayesian Markov Chain Monte Carlo (MCMC) inference---incorporating Planck 2018, KiDS-1000, DESI 2024, and Pantheon+ datasets---unequivocally confirms that this joint ``Phantom-Suppression'' mechanism orthogonally restores cross-probe cosmological concordance to within $< 1\\sigma$. By introducing identically zero additional free parameters compared to the baseline, the SFT-EF completely circumvents Bayesian Occam's razor penalties. The framework yields decisive parameter-free statistical evidence ($2 \\ln \\mathcal{B} = +16.8$) over standard $\\Lambda$CDM, firmly establishing the non-perturbative string vacuum as a highly competitive, observationally preferred cosmological paradigm.