* Ensure that the `--ref` flag cannot be used in conjunction with a cache ID.
* Update error handling to provide clear feedback when this condition is violated.
* Add tests to cover scenarios involving the `--ref` flag and cache ID.
* Changed the error message from "--ref cannot be used without cache key/ID" to "must provide a cache key" for clarity.
* Updated corresponding test case to reflect the new error message.
* Implemented test cases for handling the `--ref` flag in cache deletion commands.
* Added validation for using `--ref` with cache key and ID.
* Ensured proper error messages are returned for invalid usage of `--ref`.
