No-Go Theorem for Exact Yukawa Prediction in the Capacity-Coupled Dirac–Lambda Framework

This paper establishes a Tier-1 no-go theorem inside the capacity-coupled Dirac–Lambda framework: exact Yukawa ratios cannot be universally forced under record-admissible stationary realizations of the coupled spectral–determinant system. Working entirely within the Dirac–Lambda equation package (E1–E8), the result proves that: • The Yukawa parameter space modulo flavor redundancy (the P3 quotient) admits non-fine-tuned interior viability under admissible perturbations.• The spectral record functional SΩ is invariant under flavor orbits, leaving 45 independent orbit directions unconstrained.• Total saturation of the capacity constraints cannot occur without violating the no-retuning condition (B4).• Conditioning on forced quantities (gauge structure, fine-structure constant, strong CP exclusion, etc.) does not introduce new independent equations in the Yukawa sector. Together, these mechanisms imply that no selector internal to the Dirac–Lambda framework can collapse the Yukawa quotient space to a unique exact point. Exact Yukawa ratios therefore remain realization-level data rather than law-level outputs within the globally fixed scheme. The result is unconditional within the record-admissible stationary class of the Dirac–Lambda framework and does not rely on Tier-0 closure operators or external selection principles. It clarifies the rigidity boundary of the theory: gauge structure and certain scalar parameters may be forced, but exact flavor ratios are not. This paper complements constructive results on Standard Model gauge forcing and structural strong CP exclusion, providing a coherent rigidity map of the framework.