Improve Pro-only feature warning in spec/dummy initializer

Make it crystal clear that generated_component_packs_loading_strategy is a
Pro-only feature and should NOT be used without a license. The setting is
only present in spec/dummy because tests stub the ReactOnRailsPro constant.

Author: justin808

spec/dummy/config/initializers/react_on_rails.rb

@@ -42,8 +42,9 @@ def self.adjust_props_for_client_side_hydration(component_name, props)
   config.components_subdirectory = "startup"
   config.auto_load_bundle = true
 
-  # For spec/dummy tests, we use :defer to prevent component registration race conditions.
-  # This is explicitly set for testing purposes. Real user apps should rely on the Pro default (:async).
-  # Note: This setting requires React on Rails Pro in production use.
+  # IMPORTANT: generated_component_packs_loading_strategy is a React on Rails PRO feature.
+  # This is set here ONLY for spec/dummy tests which stub ReactOnRailsPro constant.
+  # DO NOT use this setting in production without a Pro license.
+  # We use :defer to prevent component registration race conditions during testing.
   config.generated_component_packs_loading_strategy = :defer
 end