A Reconstructional Quantum Theory of the Present: Entangled Read-Out, Probabilistic Actualization, and Emergent Time
Physics describes evolution, causal structure, and measurement outcomes, but lacks an accepted physical account of why one outcome-conditioned quantum situation is actual as the present. This article develops a conditional account within the reconstruction program, which places a premetric relational layer prior to spacetime dynamics. Conventional evolution specifies how states are related once a state space, time parameter, and dynamical law are supplied; continued admissible reconstruction addresses the prior realization question of which identities, laws, and successor records can remain physically well defined. The Indefinite Reconstruction Stability Principle requires readable structures and laws to survive admissible continuation and to ignore unobservable distinctions. A present is proposed to be the outcome-conditioned quantum read-out of an IRSP-stable, history-bearing reconstruction boundary. Because the underlying relational record need not factorize, its read-out is generally entangled. Admissible successors are represented by a quantum instrument; one stable record sector and its conditioned state constitute the next present without an external observer. A worked qubit measurement and a Bell-pair example connect this architecture to standard laboratory quantum science. Given an operational event-identity bridge, positivity, normalization, exclusive additivity, and a Hilbert-space read-out, Gleason representation fixes the Born form conditionally. Linear history composition implies no genuine third-order successor interference. Proper ancestry inheritance supplies conditional acyclicity, stable small-step channels recover standard effective dynamics, and spacelike confluence replaces a preferred global simultaneity surface. The result is a reconstructional architecture of present actuality with explicit premises and failure conditions, but no fitted collapse rate or microscopic actualization threshold.