Theory-3 : Measurement-Safe Wormhole Dynamics via Nonlocal Observation Currents and Information Screening

We develop Theory-3, the third step of the Nonlocal Vacuum Information Dynamics (NVID) framework, as a dynamical theory of observation backreaction in information-supported wormhole spacetimes. Building on Kuram-1 and Kuram-2, which established nonlocal vacuum response and intrinsic information-current stabilization, Theory-3 introduces a new observation current sector whose divergence represents the information injection associated with measurement processes. Observation-induced perturbations are redistributed through a causal nonlocal kernel and regulated by nonlinear screening mechanisms,yielding an effective observation source that remains bounded even under repeated measurements. This prevents runaway backreaction and preserves the stability of information-supported spacetime structures.We derive the full field equations of the theory, establish ghost-free and gradient-stable conditions, and show that the effective observation source saturates for strong measurement pulses. The theory predictsdistinct observational signatures including echo amplitude saturation, bounded phase degradation, drift renormalization, frequency-dependent transfer functions, and improved parameter reconstructionthrough signal stacking. Theory-3 therefore provides a measurement-safe extension of informationdynamicspacetime physics and completes the observational sector of the Nonlocal Vacuum Information Dynamics framework.