Use constructor instead of ad-hoc objects for various `Ref`s

packages/core/src/runtime/actor.ts

@@ -223,7 +223,7 @@ export class Facet {
         const h = nextHandle++;
         const e = {
             handle: h,
-            peer: { relay: other, target: new StopOnRetract() },
+            peer: new Ref(other, new StopOnRetract()),
             crossSpace: null,
             established: true,
         };

packages/core/src/transport/membrane.ts

@@ -55,10 +55,9 @@ export class Membrane {
     }
 }
 
-export const INERT_REF: Ref = {
-    relay: Actor.boot(() => Turn.active.stop(Turn.activeFacet)).root,
-    target: {},
-};
+export const INERT_REF = new Ref(
+    Actor.boot(() => Turn.active.stop(Turn.activeFacet)).root,
+    {});
 
 export interface ProxyInbound {
     proxyPacket(packet: IO.Packet<Embedded<WireRef>>): void;