Fixes: 1) Correct `.dockerignore` entry for the relocated `storefront/Dockerfile`;
Extra: 1) Refactor file structure by renaming `Dockerfile.storefront` to `storefront/Dockerfile`.
Fixes: 1) Update `docker-compose.yml` to use `Dockerfile.app` instead of default build context;
Extra: 1) Add commented-out `storefront` service in `docker-compose.yml` for potential future use; 2) Minor cleanup and structuring of Docker setup;