agent-platform release v4.84.0

modelManager.route: model-manager’s REST route, its JWT policy and the data-plane legs of its network policies (giantswarm/agent-platform#271). The portal, agents and the agentlab proofs reach model-manager through muster as the signed-in person (its MCPServer CR, x_model-manager_*), so nothing called the route. The connectivity chart renders no AgentgatewayBackend, HTTPRoute or AgentgatewayPolicy for model-manager, its ingress policy admits muster, additionalPeers and the probes, and dataplane-to-model-manager is gone in both flavours. A set modelManager.route fails the render naming the issue; model-manager’s oauth.baseURL stays https://agentgateway.<global.domain>/model-manager. agentManager.route, kagent.controllerRoute and gateway.jwksEgress are unchanged. UPGRADE.md.