Fix invalid precompile_hook

Author: alexeyr

react_on_rails_pro/spec/dummy/bin/shakapacker-precompile-hook

@@ -6,9 +6,9 @@
 # This script loads the shared test helper implementation.
 # For production apps, use the generator template which includes a standalone implementation.
 
-# Find the gem root directory (four levels up from react_on_rails_pro/spec/dummy/bin)
-gem_root = File.expand_path("../../../..", __dir__)
-shared_hook = File.join(gem_root, "spec", "support", "shakapacker_precompile_hook_shared.rb")
+# Find the repo root directory (four levels up from react_on_rails_pro/spec/dummy/bin)
+repo_root = File.expand_path("../../../..", __dir__)
+shared_hook = File.join(repo_root, "react_on_rails", "spec", "support", "shakapacker_precompile_hook_shared.rb")
 
 unless File.exist?(shared_hook)
   warn "❌ Error: Shared precompile hook not found at #{shared_hook}"