Add documentation and example env var to docker-compose.yml for running with rootless Podman. Introduces a commented ROOTLESS_CONTAINER option that, when set to "true", skips gosu UID/GID switching since user namespaces handle mapping; includes a warning not to enable this for Docker or LXC to avoid creating files as root.
Introduces a docker-compose.yml for containerized deployment of the application, including volume mappings and environment variable documentation. Updates files-hash utility to normalize path separators to forward slashes, ensuring cross-platform consistency when extracting basenames.