Fix FOUC by moving stylesheets to head and disabling auto_load_bundle

Problem:
- Stylesheets were loading at bottom of body, causing FOUC with SSR
- Moving stylesheet_pack_tag to head failed because react_component
  with auto_load_bundle=true would call append_stylesheet_pack_tag
  during rendering, which must come before stylesheet_pack_tag

Solution:
- Set auto_load_bundle = false in react_on_rails config
- Manually specify required packs in layout (stimulus-bundle)
- Move stylesheet_pack_tag to head after append calls
- This ensures styles load before content renders, preventing FOUC

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

Co-Authored-By: Claude <noreply@anthropic.com>

Author: justin808

app/views/layouts/application.html.erb

@@ -6,6 +6,7 @@
   <title>RailsReactTutorial</title>
 
   <%= append_stylesheet_pack_tag('stimulus-bundle') %>
+  <%= stylesheet_pack_tag(media: 'all', 'data-turbolinks-track': true) %>
   <%= append_javascript_pack_tag('stimulus-bundle') %>
   <%= append_javascript_pack_tag('stores-registration') %>
 
@@ -20,7 +21,6 @@
 
   <%= react_component "Footer" %>
 
-  <%= stylesheet_pack_tag(media: 'all', 'data-turbolinks-track': true) %>
   <%= javascript_pack_tag('data-turbolinks-track': true, defer: true) %>
 
   <!-- This is a placeholder for ReactOnRails to know where to render the store props for

config/initializers/react_on_rails.rb

@@ -4,7 +4,7 @@
 ReactOnRails.configure do |config|
   # Auto-registration configuration for v16
   config.components_subdirectory = "ror_components"
-  config.auto_load_bundle = true
+  config.auto_load_bundle = false
 
   config.build_test_command = "RAILS_ENV=test bin/shakapacker"
   config.build_production_command = "RAILS_ENV=production NODE_ENV=production bin/shakapacker"