Planck-Scale Fluctuation Closure as the Substrate Interpretation of the Quantized Dimensional Ledger: A QDL Capstone on Physical Persistence, Compton–Gravity Thresholds, Mass-Ratio Closure, Vacuum Filtering, and EFT Audits

This Zenodo full-version capstone develops the substrate interpretation of the Quantized Dimensional Ledger as a residual-first closure-admissibility framework for physical persistence. The substrate is not treated as a mechanical medium, classical aether, or hidden material substance; it is defined as the closure-persistent residue of candidate Planck-scale fluctuation structure. The paper identifies the Quantized Dimensional Cell, with signature L^3 F^2, as a minimal persistence cell combining spatial occupancy with second-order recurrence. It derives a dimensionless Compton-gravity closure threshold by equating the reduced Compton wavelength with the Schwarzschild radius, giving chi_CG = 2(m/m_P)^2 and the threshold m_* = m_P / sqrt(2). This threshold is not introduced as a new empirical constant, but as the point at which quantum recurrence localization and gravitational radius coincide. The paper also presents a charged-lepton mass-ratio reconstruction based on the Koide occupancy-amplitude cone and the conditional QDL relational phase theta_l = 2/9, giving a muon-electron mass-ratio estimate of 206.7703159727 compared with the observed value 206.7682827. This result is explicitly framed as a constrained dimensionless reconstruction, not a completed first-principles derivation of all lepton masses. Additional components include a gravitational QDC-to-curvature bridge, a measurement-chain closure theorem, an interpretation of constants as inter-sector closure operators, a dark-sector separation classification, a vacuum-filter toy model reducing a formal count of 216 modes to one admissible gravitational residual, and a provisional SMEFT operator-mixing audit protocol. The EFT/operator component is stated as a falsifiable audit criterion rather than a validated universal selection rule: anomalous-dimension mixing should preserve a declared QDL closure vector or exhibit an explicit admissible compensating insertion. A machine-readable SMEFT Γ(O) audit companion has been released separately as a related Zenodo dataset: Bourassa, J. D. (2026). QDL SMEFT Γ(O) Audit Companion v1.0: A Representative Source-Anchored Subset for Closure-Vector Classification of Warsaw-Basis Operator Mixing (v1.0) [Data set]. Zenodo. DOI: 10.5281/zenodo.20357001. That companion provides representative Warsaw-basis operator assignments, exact/source-anchored audit rows, strict-zero and compensator targets, a verification taxonomy, data dictionary, changelog, sources table, README, workbook, and package ZIP. It is explicitly a representative source-anchored audit subset and scaffold, not a completed full 2499 x 2499 SMEFT anomalous-dimension matrix audit. This version is intended as a QDL architecture and definitions record for future shorter papers and technical companions. It does not claim a completed derivation of the Standard Model, all masses, quantum gravity, the cosmological constant, dark matter, dark energy, or a final theory of everything. Its purpose is to define the QDL substrate interpretation and identify exact technical tests that can strengthen, revise, or falsify the program.