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;
Replaced Debian's PostgreSQL client with version 17 and added the PostgreSQL apt repository for more control over versions. Switched from `apt` to `apt-get` for consistency, and included necessary dependencies like `wget` and `gnupg` for repository setup.
The addition of `postgresql-client` ensures tools relying on PostgreSQL are available within the container. This change improves compatibility with PostgreSQL-based workflows and resolves potential missing dependencies.
