Refactor CallbackRegistry and clientStartup initialization

- Move `initializeTimeoutEvents()` call to `getOrWaitForItem()` method in CallbackRegistry
- Remove unnecessary 4-second delay in clientStartup
- Clean up commented-out webpack configuration in clientWebpackConfig

node_package/src/CallbackRegistry.ts

@@ -15,7 +15,6 @@ export default class CallbackRegistry<T> {
 
   constructor(registryType: string) {
     this.registryType = registryType;
-    this.initializeTimeoutEvents();
   }
 
   private initializeTimeoutEvents() {
@@ -75,6 +74,7 @@ export default class CallbackRegistry<T> {
   }
 
   getOrWaitForItem(name: string): Promise<T> {
+    this.initializeTimeoutEvents();
     return new Promise((resolve, reject) => {
       try {
         resolve(this.get(name));

node_package/src/clientStartup.ts

@@ -21,7 +21,6 @@ function reactOnRailsPageUnloaded(): void {
 }
 
 export async function clientStartup(context: Context): Promise<void> {
-  await new Promise((resolve) => setTimeout(resolve, 4000));
   // Check if server rendering
   if (!isWindow(context)) {
     return;

spec/dummy/config/webpack/clientWebpackConfig.js

@@ -9,10 +9,6 @@ const configureClient = () => {
   // client config is going to try to load chunks.
   delete clientConfig.entry['server-bundle'];
 
-  // clientConfig.resolve.fallback = {
-  //   ...clientConfig.resolve.fallback,
-  //   'process/browser': false,
-  // };
   return clientConfig;
 };