A document that is not a current-version envelope is REMOVED (one
log.info line names the key and the version found) and reported as
{ stored: false, loaded: null }, so stale documents cannot linger and
a later saveSettingsToStorage writes a fresh envelope.
Read settings from localStorage. Quota-safe.
A document that is not a current-version envelope is REMOVED (one
log.infoline names the key and the version found) and reported as{ stored: false, loaded: null }, so stale documents cannot linger and a latersaveSettingsToStoragewrites a fresh envelope.