Microscopic State Realization in a Finite-Capacity Universe Update Quanta, Capacity Saturation, and the Microphysical Origin of Latency, Erasure, and Gravity

This paper proposes a microphysical completion layer for a broader informational-thermodynamic program in which physical reality is modeled as a finite-capacity state-update process rather than as a passive archive of coexisting states. The central idea is that local physical evolution is carried by discrete update events acting on finite-capacity causal patches. Each patch possesses a bounded address space, a realized occupancy fraction, a local update clock, and an irreversible overwrite channel. Within this framework, latency arises from occupancy-dependent slowdown of update availability, entropy production arises from overwrite and deindexing of previously realized microstates, and gravitational redshift emerges as the macroscopic manifestation of occupancy-induced update slowdown. A microscopic patch Hilbert space is introduced together with occupancy operators, update operators, overwrite operators, and a saturation constraint. A minimal operator algebra is specified, a toy mean-field evolution law is derived, and a quantitative bound is obtained for a nonequilibrium history-dependent latency correction. The continuum latency field of the phenomenological theory is then recovered as a coarse-grained limit of microscopic occupancy. The construction yields a natural route to the latency potential, the covariant erasure source sector, the horizon-saturation picture, and the cosmological erasure law developed at the phenomenological level. The proposal is not presented as a completed fundamental theory, but as a structured microphysical candidate for the missing layer beneath an existing finite-capacity phenomenology connecting information, thermodynamics, gravity, black holes, and cosmology.