Address remaining review nits for merge readiness

Author: justin808

README.md

@@ -119,7 +119,7 @@ See package.json and Gemfile for versions
 1. [Babel transpiler](https://github.com/babel/babel)
 1. [Ruby on Rails 8](http://rubyonrails.org/) for backend app and comparison with plain HTML
 1. [Thruster](https://github.com/basecamp/thruster) - Zero-config HTTP/2 proxy for optimized asset delivery
-1. [Heroku deployment guide](https://devcenter.heroku.com/articles/getting-started-with-rails7)
+1. [Heroku deployment guide](https://devcenter.heroku.com/articles/getting-started-with-rails8)
 1. [Deployment to the ControlPlane](.controlplane/readme.md)
 1. [Turbolinks 5](https://github.com/turbolinks/turbolinks)
 1. [Tailwind CSS](https://github.com/tailwindlabs/tailwindcss)

client/__tests__/webpack/bundlerUtils.spec.js

@@ -80,12 +80,12 @@ describe('bundlerUtils', () => {
       expect(utils.isRspack()).toBe(true);
     });
 
-    it('throws when assets_bundler is webpack', () => {
+    it('returns true when assets_bundler is webpack', () => {
       mockConfig.assets_bundler = 'webpack';
       jest.doMock('shakapacker', () => ({ config: mockConfig }));
       const utils = require('../../../config/webpack/bundlerUtils');
 
-      expect(() => utils.isRspack()).toThrow('configured for Rspack only');
+      expect(utils.isRspack()).toBe(true);
     });
   });
 

config/webpack/bundlerUtils.js

@@ -38,14 +38,11 @@ const getBundler = () => {
 };
 
 /**
- * Validates rspack-only mode and returns true.
+ * Indicates this repository is standardized on Rspack.
  *
- * @returns {boolean} Always true after validation
+ * @returns {boolean} Always true
  */
-const isRspack = () => {
-  ensureRspack();
-  return true;
-};
+const isRspack = () => true;
 
 /**
  * Gets the CSS extraction plugin for Rspack.

config/webpack/client.js

@@ -1,4 +1,5 @@
 const devBuild = process.env.NODE_ENV === 'development';
+// Set by shakapacker dev-server for both webpack and rspack.
 const isHMR = process.env.WEBPACK_DEV_SERVER === 'TRUE';
 const { getBundler } = require('./bundlerUtils');
 const environment = require('./environment');

config/webpack/development.js

@@ -5,5 +5,6 @@ process.env.NODE_ENV = process.env.NODE_ENV || 'development';
 
 const webpackConfig = require('./webpackConfig');
 
-// Rspack HMR/refresh is handled by Shakapacker + @rspack/plugin-react-refresh.
+// Shakapacker auto-registers ReactRefreshRspackPlugin in dev-server mode
+// when @rspack/plugin-react-refresh is present.
 module.exports = webpackConfig();