Once your multi-agent system (Parts 6-8) is functionally solid, the question that comes up in every enterprise security review is the same: how do you know an agent is only doing what it's authorized to do, over a network path you actually trust, with an audit trail that holds up when someone asks "what did this agent do and why" six months later? This post covers private networking, Entra Agent ID, and audit trail design. Zero-Trust Network Boundary