Use -f instead of --force for Rails generator

Changed from --force to -f (short form) to ensure proper parsing
by the Rails generator command.

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

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

Author: justin808

lib/demo_scripts/demo_creator.rb

@@ -327,7 +327,7 @@ def install_react_on_rails
       # Remove files that will conflict with React on Rails generator
       cleanup_conflicting_files
 
-      base_args = ['--ignore-warnings', '--force']
+      base_args = ['--ignore-warnings', '-f']
       all_args = (base_args + @react_on_rails_args).join(' ')
 
       @runner.run!(