Fix webpack inspection commands to use valid options

Replace invalid --print-config with working webpack commands:
- Use --progress --verbose for debugging webpack builds
- Keep ANALYZE=true for bundle size analysis
- Add reference to actual configuration file locations

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

lib/react_on_rails/system_checker.rb

@@ -283,8 +283,9 @@ def check_webpack_configuration
     end
 
     def suggest_webpack_inspection
-      add_info("💡 To inspect webpack configuration: bin/shakapacker --print-config")
+      add_info("💡 To debug webpack builds: bin/shakapacker --progress --verbose")
       add_info("💡 To analyze bundle size: ANALYZE=true bin/shakapacker")
+      add_info("💡 Configuration files: config/webpack/webpack.config.js, config/shakapacker.yml")
     end
 
     def check_webpack_config_content