Route selection in vsms — the pure sms-routing engine with its injected random draw for deterministic replay, priority bands and weighted members, the wildcard semantics of NULL predicates, two-hop failover with a per-message exclude set, provider circuit breakers, and grey-route divergence detection. Load when changing how a message picks a provider, adding a route predicate, debugging why a message was rejected with no route, or touching either circuit breaker.
