Paper T16C2: Always-Defined Packet Readout Contracts Under EML–B Licensing Occupancy, Dropout Hazard, and Run-Length Quantiles as Decision-Grade Photon Semantics on Declared Windows

Paper T16C2 defines an audit-stable packet readout contract for photon-semantics claimsunder the Paper T16B EML–B field-language license. The objective is operational: specifypacket events and packet KPIs that remain decision-grade on declared detector sets and declaredtime windows without smoothing, interpolation, adaptive thresholding, or post hoc tuning.The central guarantee is license binding: packet semantics are asserted only on EML–Blicensed windows, and any unlicensed computations are treated as diagnostic-only readouts.Within licensed windows, T16C2 replaces recovery-dependent continuity indices that exhibitstructural undefined behavior (plateau and no-recovery cases under fixed windows) with analways-defined KPI suite: (i) licensed on-threshold occupancy, (ii) licensed dropout hazard (acontinuity surrogate), and (iii) run-length quantiles of above-threshold segments. An optionalcensored recovery lag is permitted as a supporting diagnostic with explicit censoring flags, neveras a headline KPI.This paper introduces no new engine rules, derives no Maxwell equations, and models nodetector microphysics. Its deliverable is a stable measurement contract and fixed-named artifactssuitable for governance-grade downstream use.