Detect partial volume wipes that leave legacy auth.db in /app/data while
/opt/rustdesk was reset, which broke panel login despite a fresh
.admin_credentials file. Fail fast with a clear error, remove empty orphan
auth.db on fresh installs, and document compose ADMIN_PASSWORD mapping.
Refs #385
Thanks: INSOLVE (Honorary); Marco Jakobs (@jacotec); MyNameisStitch (@MyNameisStitch); Redspin (@playerumpknow)
UNITRONIX