Serve a trusted holder from a runtime of its own account, refuse it in the machine's runtime, and say while an agent can become root where it runs (hq ADR 0259 §8)

internal/broker/users.go

@@ -50,6 +50,9 @@ type Declared struct {
 	// Checks are the module's own tools its health asks, each `<module>.<tool>` (novox/hq ADR 0240, to-be
 	// 48 §3): the machine's node-engine asks them of its own node tools, and is granted that and no more.
 	Checks []string
+	// RunsAs is the account the module runs as in a runtime of its own (novox/hq ADR 0259 §8): it is never
+	// carried by the machine's runtime, and reaches the bus on its own account.
+	RunsAs string
 }
 
 // Records is what composing a user list needs to know about the mesh, and nothing more.
@@ -120,10 +123,13 @@ func Users(r Records) ([]Principal, error) {
 			})
 		}
 		if runtimeHere {
-			out = append(out, Principal{
-				Kind: KindNodeTools, Node: node, Module: RuntimeModule,
-				Carries: append([]Declared(nil), r.Assigned[node]...),
-			})
+			var carried []Declared
+			for _, d := range r.Assigned[node] {
+				if d.RunsAs == "" {
+					carried = append(carried, d)
+				}
+			}
+			out = append(out, Principal{Kind: KindNodeTools, Node: node, Module: RuntimeModule, Carries: carried})
 		}
 	}
 	for _, node := range sortedCopy(r.Enrolling) {