refactor: Extract bin/dev comparison into separate method

Improve code organization by extracting the bin/dev default comparison
logic into a dedicated method. This makes the code more maintainable
and adds clearer documentation about why we use a hardcoded default
(Rails doesn't provide a bin/dev template).

The shakapacker.yml comparison already correctly fetches and compares
against the actual installer template from the Shakapacker gem.

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

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

Author: justin808

lib/generators/react_on_rails/install_generator.rb

@@ -77,20 +77,26 @@ def remove_default_bin_dev
         return unless File.exist?(bin_dev_path)
         return unless File.writable?(bin_dev_path)
 
-        # Rails 7+ default bin/dev content
-        # If Rails changes this default, this comparison will safely fail and preserve the file
-        default_bin_dev = <<~RUBY.strip
-          #!/usr/bin/env ruby
-          exec "./bin/rails", "server", *ARGV
-        RUBY
-
         current_content = File.read(bin_dev_path).strip
-        return unless current_content == default_bin_dev
+        return unless bin_dev_matches_rails_default?(current_content)
 
         puts Rainbow("🗑️  Removing default bin/dev file to avoid conflicts...").yellow
         FileUtils.rm_f(bin_dev_path)
       end
 
+      def bin_dev_matches_rails_default?(content)
+        # Rails 7+ simple bin/dev content
+        # Note: Rails doesn't have a bin/dev template in its generators, but this is the
+        # common simple default that many Rails apps use. We check against this known
+        # default to avoid conflicts during installation.
+        rails_simple_default = <<~RUBY.strip
+          #!/usr/bin/env ruby
+          exec "./bin/rails", "server", *ARGV
+        RUBY
+
+        content == rails_simple_default
+      end
+
       def remove_default_shakapacker_yml
         config_path = File.join(destination_root, "config/shakapacker.yml")
         return unless File.exist?(config_path)