Invariant Vacuum Crossover and Emergent Gravity: Unified Covariant Shield from Matter Invariants, EFT Cutoff Scale, Ghost-Free MOND Operator, and Environment-Emergent No-Slip Lensing

We propose a macroscopic scalar–tensor EFT where MOND-like galactic phenomenology emerges as an invariant environmental crossover of the vacuum. A single covariant order parameter W(T_eff), built from matter invariants, controls modified dynamics, screening, and lensing through a unified mechanism. The model reproduces flat rotation curves and the baryonic Tully–Fisher relation in galaxies while restoring General Relativity in dense environments. The construction is ghost-free and consistent within its EFT domain of validity.