Physics from Finite Validation: Classical Recovery and the Quantum Boundary

We develop a foundational framework in which the world is a self-validating system of mutually-confirming functional structures, and we show how the physics of our world arises from it: from the single requirement that validation is exchanged — and therefore transmitted at finite speed — the structure of known physics follows, the finite transmission limit being not an added postulate but a condition for events to be distinguishable at all. From this limit the classical sector is recovered: the Lorentz factor from interception geometry, gravitational time dilation without fitting, the full relativistic light deflection (1. 750 arcsec) as the sum of two equal channels, the perihelion advance of Mercury via a path-compounded law selected by data, the 1/r² profile as compatibility with three dimensions, an effective gravitational attraction emerging from synchronisation dynamics, and the form of E=mc² (postulated by analogy). The novelty lies in the grounding, not in the numbers, and the quantitative Newtonian limit is left open. The quantum sector is given a coherent interpretation with its boundary explicitly marked. Genuine randomness is read as the operational inaccessibility of cause under limited temporal resolution; superposition as the absence of position prior to an act of mutual validation; measurement as that binary act. Within this reading we offer a geometric reconstruction of the Tsirelson factor 2-root-2 under an explicit closure-point hypothesis (the bound of 2 derived from binarity, the factor root-2 from a Pythagorean path under party symmetry), reinterpret the Born quantity as a degree of constructedness rather than a frequency, and ground the structure of the observable quantum on the proven value indefiniteness of Kochen-Specker. The junction with gravity is demarcated through a genuine/false-quantum distinction rather than solved. We do not claim to derive the Tsirelson bound, replace the Born rule, or quantise gravity; each such item is marked as interpretation, hypothesis, or open debt. All simulation code is openly available.