Fix FOUC by moving stylesheet loading to head section

The stylesheet_pack_tag was loading at the bottom of the body,
causing a flash of unstyled content (FOUC) as React components
rendered before CSS loaded. Moving it to the head ensures styles
are loaded before content renders.

🤖 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