AgentInteractionEvent
data class AgentInteractionEvent(val timestamp: Instant = Clock.System.now(), val correlationId: String, val fromAgent: String, val toAgent: String, val eventType: String, val eventId: String? = null) : TracerEvent
Records an inter-agent interaction. Emitted by Dispatcher / Router once the Phase 4 agent system ships; declared here so consumers can register interest immediately.