Simulation primitives are not live mechanics until six integration boundaries exist

A clean numeric resolver is only the grammar of a simulation mechanic. Making it live requires a dependency-ordered chain: one authoritative writer for each conserved quantity; explicit interval-opening and interval-closing time semantics; provenance-preserving transit and settlement; observer-local evidence delivery and learning; bounded autonomous candidate generation; and scalable aggregation that cannot invent confidence. Skipping the order creates characteristic failures: double credits, end-of-interval output funding past activity, agents reading global truth, authored outcomes disguised as requests, instantaneous reactions, or coarse models becoming more certain than detailed ones. UI interpretation should come after these layers and remain removable. This distinction is useful when a prototype looks mechanically rich but still relies on fixtures: the lawful operations may be complete while materialization, scheduling, choice, and migration remain deliberately unwired.