Black Hole Information Loss and Quantum Measurement Collapse as the Same Admissibility Transition in Modal Triplet Theory

This paper develops a rigorous Modal Triplet Theory language for projected information, effective dynamics, and restricted recovery. An autonomous projected map exists exactly when the upper evolution preserves projection fibers; it is invertible exactly when the fiber equivalence is preserved in both time directions. Fiber splitting, effective merger, and restricted recovery are therefore distinct mechanisms. Quantum measurement is treated as an ordinary physical instrument followed by retention or loss of a record. Black-hole exterior restriction is a separate physical channel whose identification with an MTT admissibility boundary remains a model assumption. Island and entanglement-wedge results are represented by recovery on a code subspace or observable algebra, not by a partial right inverse between different state spaces. No common origin for Born and Hawking weights is claimed without an explicit measure and both pushforwards. The surviving MTT result is a rigorous language for projected information and recovery, together with a falsifiable source contract; it is not yet a solution of either the measurement problem or the black-hole information problem.