Physics from Finite Validation: Vacuum Energy, Quanta as Constituents of the Vacuum, and the Double-Slit Assembly

In the preceding work we presented the world as a self-validating system — existence as mutual confirmation transmitted in finite time — and recovered classical physics from that single requirement, with the quantum sector given a coherent interpretation and an explicit boundary. Here we carry the construction to the vacuum. The vacuum is presented as a network whose nodes are normal particles and whose links are quantum acts: neither component exists without the other, and quanta are therefore constituents of the vacuum rather than residents in it. From this construction follow, each with its stated status: a structural reading of virtual particles (four known properties from one closed configuration); the removal of the vacuum catastrophe by a physical criterion of participation — the synchronised-cluster mean replaces the sum over modes, and the residue law ε = σ²/(2K²), derived analytically and confirmed numerically (R² = 0.9992), shows the 10^120 discrepancy to be a category error, an extensive sum compared against an intensive residue; a translation of the cosmological-constant problem from fine tuning into node homogeneity (σ/K ≈ 5×10⁻⁶²), with quantum identity as a motivating analogy and the value of Λ itself left underived; the photon read as confirmation transfer, with the limit c as the network's tick tempo and masslessness as zero delay; isotropy of an ordered network through the geometrylessness of quantum links; and a double-slit study in which the dynamics delivers a distribution while the point is chosen by the act of assembly — with the Born square given, for the first time in this programme, a structural carrier: the square of the tick, and asymmetric-slit setups identified as the discriminator between assembly hypotheses. Every claim carries its status; six open debts are named, the bridge between the two model regimes first among them. The record contains two files: the main article and the Numerical Companion (full simulation protocols, seeds, and per-result status labels). Code: https://github.com/ivan-denysov/finite-validation-vacuum