setup.sh fails for non-root sudo users: "docker is installed but the daemon is not running" (actually a permission error on docker.sock)

## Describe the bug The one-line installer documented at https://supabase.com/docs/guides/self-hosting/docker (`curl -fsSL https://supabase.link/setup.sh | sh`) fails when run as a regular user with sudo privileges — the default account on cloud-init provisioned VMs (Ubuntu, Debian, etc.). `setup.sh` installs and starts Docker via `$SUDO`, but every subsequent `docker` invocation runs without it, and the script never adds the invoking user to the `docker` group. Since a freshly created user has no permission to access `/var/run/docker.sock`, the first non-sudo docker call fails. The failure surfaces in `utils/add-new-auth-keys.sh`, which is called from `setup.sh` (`sh utils/add-new-auth-keys.sh --update-env`). When Node.js >= 16 is not installed, the script falls back to Docker and runs: ```sh if ! docker info >/dev/null 2>&1; then echo "Error: docker is installed but the daemon is not running." exit 1 fi ``` Because stderr is discarded, a `permission denied` on the docker socket is reported as "daemon is not running", which is misleading — the daemon *is* running (`sudo systemctl is-active docker` → `active`). Even if this step passed (e.g. with Node.js present), the subsequent `docker compose pull` in `setup.sh` would fail the same way, only emit a warning, and the script would still print "Setup complete", deferring the failure to `sh run.sh start`. ## To Reproduce 1. Fresh Ubuntu 26.04 VM (cloud-init), logged in as the default sudo-enabled user (not root), no Docker and no Node.js installed. 2. Run `curl -fsSL https://supabase.link/setup.sh | sh` 3. Accept/fill in the URL prompts. Output (abridged): ``` ===> Enabling and starting docker service Synchronizing state of docker.service with SysV service script ... ===> Sparse-cloning supabase repo at self-hosted/v0.8.0 ===> Creating project at /home/<user>/supabase-project ... ===> Generating secrets and legacy API keys Updating .env... ===> Generating asymmetric key pair and opaque API keys Error: docker is…