Variational Backbone and Regime Closures XI: Quantum Mechanics as a Representation-Layer Readout in R3 Probability and measurement as operational instances and gates

Quantum mechanics is formulated here as a Representation-Layer readout on the conservative (time-completed) R3 dynamics generated by a fixed variational backbone E. TheStructural Layer contributes no probabilistic postulates: it provides a conserved density–current pair and its continuity law, while Born probabilities and measurement updates arisesolely as explicit operational instances together with a measurement gate. Classical mechanicsappears as a regime inside the same R3 dynamics at fixed ℏ, rather than as an ℏ → 0 limit.The measurement gate is written as an instance of the observational projection channel ofPart IV, and a short appendix records how the familiar Schrödinger representation fits as anoperator instance on the same conserved pair.