The reader can add a book with a title and author, view the books in the order added, and remove a book. An empty title or author is rejected with a clear error message. The application includes automated tests for each behavior. The completed application provides a POSIX-compatible `bin/test.sh` that runs the complete automated test suite from the application root. `sh bin/test.sh` exits zero only when every test passes. The final build story runs this command after every implementation story and preserves its command, exit code, standard output, and standard error as evidence.