Add mcp dns and mcp node routes commands

mcp dns queries MCNS via an agent to list all zones and DNS records.
mcp node routes queries mc-proxy on each node for listener/route status,
matching the mcproxyctl status output format.

New agent RPCs: ListDNSRecords, ListProxyRoutes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/agent/proxy.go

@@ -48,6 +48,14 @@ func (p *ProxyRouter) Close() error {
 	return p.client.Close()
 }
 
+// GetStatus returns the mc-proxy server status.
+func (p *ProxyRouter) GetStatus(ctx context.Context) (*mcproxy.Status, error) {
+	if p == nil {
+		return nil, fmt.Errorf("mc-proxy not configured")
+	}
+	return p.client.GetStatus(ctx)
+}
+
 // RegisterRoutes registers all routes for a service component with mc-proxy.
 // It uses the assigned host ports from the registry.
 func (p *ProxyRouter) RegisterRoutes(ctx context.Context, serviceName string, routes []registry.Route, hostPorts map[string]int) error {