The app's health check ran on the target host against the container name, which
only resolves inside the Docker network, so the wait could never succeed. Poll
the image's HEALTHCHECK instead and fail with a readable message. Also pin
site.env to the app user when it exists, and say how to install the provisioning
script on the server.
Deploys the menu app for one Site: pulls the tag, creates the data root, runs
the container against a config baked into the image, waits for health, verifies
the data directory, and points Caddy at the app with a marker it can update in
place. The parallel run uses a temporary hostname; cutover sets the retire
flags.
tanshu