Fix store payment options iterator

[toaditi]

Summary

• Guard the ProductStorePaymentSetting iterator with hasNext() before calling next().
• Prevent NoSuchElementException when rendering order entry payment options after the final payment setting row.

Validation

• git diff --check HEAD~1..HEAD
• Pre-push Gradle hook completed successfully: compileJava, compileGroovy, checkstyleMain, codenarcMain