Marker for internal/infrastructure messages that should NOT get a per-message process span
or processing metrics. ActorCell skips instrumentation for messages implementing this.
Use it on high-frequency control messages — timer ticks, coalesced liveness signals — whose
per-message telemetry adds no diagnostic value and, on a single-core reactor, perturbs
timing-sensitive loops (a failure detector measuring inter-arrival times is skewed if each of
its own tick messages mints and exports a span; the instrumentation disturbs what it observes).
Application messages should never implement this.
Nexus API Reference