- Added `recoverOrphanedBackups` to promote `.jsonl..bak` files back to their primary path when the primary is missing, preventing data loss after a mid-rename crash.
- Changed backup filename from dot-prefixed to plain `..bak` so the shared `*.bak` glob can find it on both real and in-memory storage backends.
- Surfaced the original EPERM as the error `cause` and included both original and retry messages when rollback also fails.