PR #303 loads the entry when the first poll fails. Measured on its
branch, that produces an entry with zero bound entities and zero
coordinator listeners, so DataUpdateCoordinator never reschedules and
the device never recovers without a manual reload.
Record why entities can't be created offline here (discovery is the only
source of `bound`, and platforms enumerate it once), what a working
version would need (persisted discovery snapshot, reconcile-on-reconnect,
a listener that keeps polling alive), and the cheaper retry-and-reload
option that solves the filed issue on its own.
Marc Billow
bc03ada208