Substrate theory is a theoretical framework for fundamental physics built from eight foundational postulates and four free parameters. The framework derives the rest of physics from this minimal axiomatic base: gravity, the equivalence principle, special and general relativity, the Born rule, the Standard Model gauge group, fermion masses, the inflation observables, the matter-antimatter asymmetry, the MOND scale, the dark energy density, the Bekenstein-Hawking black hole entropy, and the cascade of new physics beyond the Standard Model. This document is the complete catalog of substrate-theory predictions: what they are, how they will be tested, and when. The framework's most distinctive predictions cluster around three sectors that current and next-generation experiments will probe over the next two decades: • Decoherence sector. The energy-eigenstate formula γ = (ΔE/M_P c²)² × ν_P predicts thermal molecular interferometry coherence times scaling as τ ∝ 1/T². No competing intrinsic-decoherence framework predicts this exact dependence. Testable in molecular interferometers (Quanta-MIM, KDTL-IM) over 2025-2030. • B-physics sector. Cascade Z bosons at Bessel-zero masses (Z₁ = 2.95 TeV, Z₂ = 5.4 TeV, Z₃ = 7.83 TeV) and Wilson coefficient ΔC₉ = -0.93 ± 0.20. Six-test experimental program runs from HL-LHC and LHCb (2025-2032) through FCC-hh (2045+). • Inflation and cosmology sector. Tensor-to-scalar r ≈ 0.003, non-Gaussianity f_NL ≈ 0.014, cascade gravitational wave background at 1 mHz. Testable by CMB-S4, LiteBIRD, and LISA on a 2028-2038 timetable. The framework is concretely falsifiable. Each test specifies what outcome would refute or confirm it. The next twenty years of experiments will tell us whether substrate theory describes how the universe actually works.