Modal Triplet Theory and Quantum Field Theory on Curved Spacetime: A Selected Free CAR Net and the Interacting Reconstruction Boundary

The current Modal Triplet Theory corpus supports a precise but limited curved-spacetime quantum-field-theory result. On the selected globally hyperbolic framed q79 representative, a global coframe and parallel rank-six carrier define a zero-order-free twisted massless Dirac operator. Standard algebraic QFT then yields an even CAR observable net with locality, covariance, the time-slice property, and a nonempty positive Hadamard state space, together with the exact finite coherent/complement component map. These conclusions use independent QFT theorems; they are not derived from projection alone. At nonzero interaction, the selected carrier has a classical BV master-action and formal perturbative QME/equicausal construction, while a physical nonperturbative gauge-BRST C-star net, selected state, renormalization-group matching, and observable uncertainty packet remain open. The paper also separates Hadamard regularity from unitary implementability, and treats the semiclassical Einstein equation and FRW particle production as conditional applications. This establishes a selected free local QFT source and a formal interacting bridge, not a first-principles derivation of full interacting QFT from finite projection.