fix(rsc-mf): register callback for federated action runtime copy

Author: cursoragent

tests/integration/rsc-mf/host/src/server-component-root/HostRemoteActionRunner.tsx

@@ -1,10 +1,11 @@
 'use client';
 
-import { useState } from 'react';
+import { useEffect, useState } from 'react';
 import RemoteClientBadge from 'rscRemote/RemoteClientBadge';
 import { RemoteClientCounter as RemoteClientCounterBridge } from 'rscRemote/RemoteClientCounter';
 import { remoteActionEcho } from 'rscRemote/actions';
 import defaultRemoteAction from 'rscRemote/defaultAction';
+import { registerRemoteServerCallback } from 'rscRemote/registerServerCallback';
 
 export default function HostRemoteActionRunner() {
   // Keep this import in the client graph so federated RSC bridge IDs
@@ -14,6 +15,10 @@ export default function HostRemoteActionRunner() {
   const [echoResult, setEchoResult] = useState('');
   const [isPending, setIsPending] = useState(false);
 
+  useEffect(() => {
+    registerRemoteServerCallback(window.location.origin);
+  }, []);
+
   const runActions = async () => {
     setIsPending(true);
     try {