Quantum Proper-Time Clocks as Temporal Interfaces: A Diagnostic Note on Clockability, Proper Time, and Temporal Exportability

This technical note treats recent work on quantum signatures of proper time in optical ion clocks as an external stress reference for the Clockability cluster. The note does not propose a new theory of time, nor does it interpret quantum optical clocks as confirming Clockability. Instead, it distinguishes proper-time accumulation, physical clock readout, trace comparability, and temporal exportability as separate descriptive levels. Optical ion clocks are analyzed as temporal interfaces: finite physical architectures through which proper-time signatures become accessible under specific conditions of state preparation, motional structure, coherence, and readout. The aim is diagnostic only: to clarify how high-precision quantum-clock regimes make visible the distinction between local proper-time dynamics and the operational availability of temporal order.