This preprint develops a falsifiable closure program in which Planck’s constant is interpreted as an emergent “action-per-update” invariant within an open effective field theory (Open-EFT): an observed brane sector M coupled to an unobserved bath B. The goal is not a scale-free, purely logical derivation of the SI numerical value of Planck’s constant, but a sharply stated phenomenological closure that makes correlated predictions and admits decisive failure modes. The central proposal is an effective-channel relation for an emergent action scale: hbar_eff ≈ (rho_Lambda * R_star^4 / c) * (eta^3 * xi) where rho_Lambda is the observed vacuum energy density, R_star is a brane-projected correlation/registration tick length (interpretable as a warp-redshifted “bulk tick”), and eta and xi are order-one operational matching factors between a coarse-grained cell size and the bath-registration time. A basal Landauer-voxel closure is stated explicitly: rho_Lambda ≈ (k_B * T_bulk * ln 2) / (ell_c^3) together with a warped 5D Randall–Sundrum template and Goldberger–Wise radion stabilization to relate microscopic and projected scales. All non-standard assumptions are separated from derived consequences. Falsifiability is emphasized. The program is ruled out if no parameter region simultaneously: (i) reproduces the laboratory value of Planck’s constant via the closure, (ii) satisfies KK-gap consistency under the chosen warped background and localization, and (iii) remains compatible with macroscopic-coherence constraints if the tick is operational. Depending on the Open-EFT kernel realization, additional exclusion arises if the bath coupling generates a static short-range Yukawa channel already ruled out by torsion-balance tests. The manuscript specifies a reproducible scan protocol and sensitivity diagnostics; a complete assessment requires scan outputs and, ultimately, an explicit Open-EFT influence kernel to compute the static response and decoherence functional. Author: Dario Peyru (MetaTime Research Program, Pilar, Buenos Aires, Argentina)Date: February 2026