Print loaded configuration

You can print the configuration that docker-volume-backup has picked up without running a backup:

docker exec <container_ref> backup print-config

If configuration sourcing fails, the error is printed to stdout to aid debugging.

If you want to test a one-off value, pass it directly:

docker exec -e BACKUP_SOURCES=/backup -e NOTIFICATION_URLS=stdout:// <container_ref> backup print-config

Output includes secrets exactly as loaded.

This feature is still in development and might change in future releases.