Resolve history accumulation (20 snapshots + sort -u) is only useful
for domain lists where DNS round-robin returns different IPs each time.
For IP/subnet-only lists (like antifilter-ip6 with 127k entries),
every snapshot is identical, making the merge a waste of ~77 minutes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>