Changing a host's restic_paths spawns a new snapshot group (restic groups by host+paths), so old and new path-sets each keep their own retention lineage. Surfaced while extending majorlab's backup scope.
Architecture, per-engine DB dump patterns, restore procedure, add-a-host, and gotchas (RESTIC_CACHE_DIR/$HOME, missing sqlite3, docker dump env vars, delete-capable B2 key). Linked in SUMMARY under storage-backup.
