Move immediate_hydration config from core to Pro initializers

Moved immediate_hydration configuration from ReactOnRails initializers to
ReactOnRailsPro initializers in dummy apps, reflecting the migration of this
Pro feature from the core gem to the Pro gem.

Changes:
- Removed config.immediate_hydration from spec/dummy core initializer
- Added config.immediate_hydration = true to Pro initializers in:
  - react_on_rails_pro/spec/dummy
  - react_on_rails_pro/spec/execjs-compatible-dummy

Note: Explicitly set to true to match Pro gem's default and demonstrate
the Pro feature is enabled in Pro dummy apps.

Author: AbanoubGhadban

react_on_rails_pro/spec/dummy/config/initializers/react_on_rails_pro.rb

@@ -39,6 +39,9 @@
   # include any files used to generate the JSON props.
   config.dependency_globs = [File.join(Rails.root, "app", "views", "**", "*.jbuilder")]
 
+  # Enable immediate hydration (Pro default is true, explicitly set for clarity)
+  config.immediate_hydration = true
+
   # When using the Node Renderer, you may require some extra assets in addition to the bundle.
   # The assets_to_copy option allows the Node Renderer to have assets copied at the end of
   # the assets:precompile task or directly by the

react_on_rails_pro/spec/execjs-compatible-dummy/config/initializers/react_on_rails_pro.rb

@@ -27,4 +27,7 @@
   # You can run rake react_on_rails_pro:process_v8_logs to process these files and generate a profile.v8log.json file
   # which can be analyzed using tools like Speed Scope (https://www.speedscope.app) or Chrome Developer Tools
   config.profile_server_rendering_js_code = true
+
+  # Enable immediate hydration (Pro default is true, explicitly set for clarity)
+  config.immediate_hydration = true
 end

spec/dummy/config/initializers/react_on_rails.rb

@@ -41,6 +41,5 @@ def self.adjust_props_for_client_side_hydration(component_name, props)
   config.rendering_props_extension = RenderingPropsExtension
   config.components_subdirectory = "startup"
   config.auto_load_bundle = true
-  config.immediate_hydration = false
   config.generated_component_packs_loading_strategy = :defer
 end