podman builds an OCI image by default and drops the Dockerfile's HEALTHCHECK
instruction, so the first deploy failed at "Wait for the container healthcheck
to pass" with "container ... has no defined healthcheck" even though the app was
up and healthy.
- Declare the same check on the greatbear.container unit (HealthCmd plus
interval, timeout, retries, start period), the convention hops and menu-admin
already use.
- Flush handlers right after starting, before the gate: the unit template's
restart handler otherwise runs at the end of the play, so a run that changes
only the unit would test the stale container.
Mirrors hops 7366596, so the two deployments keep the same shape.