- Document routes6.d/ structure and IPv6 processing
- Add GRE tunnel + NPTv6 prefix translation diagram
- Document "default" keyword behavior for IPv4/IPv6
- Document IPv4 filtering in IPv6 mode
- Document automatic rules/routes recovery
- Note routes.d/ and routes6.d/ are site-specific (not in git)
- Update state section with gateway tracking
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>