Supplementary Note to UDCT v2.6: Numerical Verification of Self-Regulating Vacuum Dynamics and Framework for Electroweak Gauge Integration

This record contains the Supplementary Note to Unified Dimensional Cohesion Theory (UDCT) v2.6. It provides detailed numerical verification of self-regulating vacuum dynamics using a 3D pseudo-spectral simulator, confirming that the bidirectional projection operator Ψ_BD drives stable vacuum behavior without UV fine-tuning. The note also presents the mathematical framework for extending the geometric back-reaction mechanism from a scalar toy model to the full SU(2)_L × U(1)_Y electroweak gauge sector. The complete Python simulator code used to generate Figure 1 is included for full reproducibility (random seed fixed at 42).