Interface Precipitation Universe (IPU) Theory v4.0: Unified Resolution of Cosmological Anomalies via Topological Vacuum Tension

The standard cosmological model (LambdaCDM) typically explains flat galactic rotation curves via dark-matter halos with multiple free parameters, often raising fine-tuning concerns (e.g., the disk-halo conspiracy). This supplement replaces empirical interpolation functions with an asymptotically consistent IPU kinematic equation. Using a fixed visible-mass model (bulge + exponential disk) and a representative Gaia-based kinematic profile, we fit a single constant parameter and evaluate whether the rotation curve can remain flat purely by (i) the 1/r decay of the baryonic term and (ii) the emergence of an interface-driven constant term. We show that a uniform constant term (no screening) fails under the fixed baryonic model, whereas an interface-exposure factor derived from the same disk scale length yields a smooth transition and substantially improves the weighted fit while preserving the Newtonian inner limit.