Solves GOV-02 (gravity-only + dissipation):
∂²χ/∂t² = c²∇²χ − κρ − γ∂χ/∂t

Full GOV-02 includes −4λ_H·χ(χ²−χ₀²) Mexican hat self-interaction, negligible at GW astrophysical scales (Δχ/χ₀ ~ 10⁻⁶).

Near edges: χ → ∞ exponentially, so c_eff → 0 (waves slow) and γ → large (waves dissipate like redshifting photons).

Result: waves approach but never reach the "edge" - the universe appears infinite.