Run RSpec for minimum version examples with bundler isolation

Add unbundled option to run_tests_in to use unbundled_sh_in_dir for
minimum version example tests. This ensures the example app's Gemfile
and gem versions are used (e.g., Shakapacker 8.2.0) instead of the
parent workspace's bundle context (which has Shakapacker 9.4.0).

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

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

Author: justin808

react_on_rails/rakelib/run_rspec.rake

@@ -82,7 +82,10 @@ namespace :run_rspec do
     puts "Creating #{example_type.rspec_task_name} task"
     desc "Runs RSpec for #{example_type.name_pretty} only"
     task example_type.rspec_task_name_short => example_type.gen_task_name do
-      run_tests_in(File.join(examples_dir, example_type.name)) # have to use relative path
+      # Use unbundled mode for minimum version examples to ensure the example app's
+      # Gemfile and gem versions are used, not the parent workspace's bundle
+      run_tests_in(File.join(examples_dir, example_type.name),
+                   unbundled: example_type.minimum_versions?)
     end
   end
 
@@ -158,11 +161,17 @@ end
 # If string is passed and it's not absolute, it's converted relative to root of the gem.
 # TEST_ENV_COMMAND_NAME is used to make SimpleCov.command_name unique in order to
 # prevent a name collision. Defaults to the given directory's name.
+# Options:
+#   :command_name - name for SimpleCov (default: dir basename)
+#   :rspec_args - additional rspec arguments (default: "")
+#   :env_vars - additional environment variables (default: "")
+#   :unbundled - run with unbundled_sh_in_dir for Bundler isolation (default: false)
 def run_tests_in(dir, options = {})
   path = calc_path(dir)
 
   command_name = options.fetch(:command_name, path.basename)
   rspec_args = options.fetch(:rspec_args, "")
+  unbundled = options.fetch(:unbundled, false)
 
   # Build environment variables as an array for proper spacing
   env_tokens = []
@@ -171,5 +180,11 @@ def run_tests_in(dir, options = {})
   env_tokens << "COVERAGE=true" if ENV["USE_COVERALLS"]
 
   env_vars = env_tokens.join(" ")
-  sh_in_dir(path.realpath, "#{env_vars} bundle exec rspec #{rspec_args}")
+  command = "#{env_vars} bundle exec rspec #{rspec_args}"
+
+  if unbundled
+    unbundled_sh_in_dir(path.realpath, command)
+  else
+    sh_in_dir(path.realpath, command)
+  end
 end