The pre-existing s3:// / gcs:// custom-logger tests called
``get_instance_fn`` without ``config_file_path``, which means the
new runtime gate (refuse remote URLs unless invoked from a
config-file load) now raises ``ValueError`` before reaching the
mocked download paths. Each test was exercising the documented
startup config-file load scenario; pass ``config_file_path="/any/path"``
to make that intent explicit and route past the gate.
Affected: test_s3_download_success, test_gcs_download_success,
test_invalid_url_format, test_download_failure_handling,
test_file_cleanup.