Simplify CSS loader configuration using optional chaining

Replace verbose defensive coding with cleaner optional chaining and simpler array find pattern. The fix only applies if namedExport is enabled, which is not currently the case but may be in future Shakapacker versions. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>

Author: justin808

config/webpack/commonWebpackConfig.js

@@ -51,23 +51,15 @@ if (sassLoaderIndex !== -1) {
  }
 }
 
-// Fix css-loader configuration for CSS modules
+// Fix css-loader configuration for CSS modules if namedExport is enabled
 // When namedExport is true, exportLocalsConvention must be camelCaseOnly or dashesOnly
-const cssLoaderIndex = scssRule.use.findIndex((loader) => {
- if (typeof loader === 'string') {
- return loader.includes('css-loader');
- }
- return loader.loader && loader.loader.includes('css-loader');
+const cssLoader = scssRule.use.find(loader => {
+ const loaderName = typeof loader === 'string' ? loader : loader?.loader;
+ return loaderName?.includes('css-loader');
 });
 
-if (cssLoaderIndex !== -1) {
- const cssLoader = scssRule.use[cssLoaderIndex];
- if (typeof cssLoader === 'object' && cssLoader.options && cssLoader.options.modules) {
- // If namedExport is enabled, ensure exportLocalsConvention is properly set
- if (cssLoader.options.modules.namedExport) {
- cssLoader.options.modules.exportLocalsConvention = 'camelCaseOnly';
- }
- }
+if (cssLoader?.options?.modules?.namedExport) {
+ cssLoader.options.modules.exportLocalsConvention = 'camelCaseOnly';
 }
 
 baseClientWebpackConfig.module.rules[scssConfigIndex].use.push(sassLoaderConfig);