savegame 2026-08-09: geneve-over-v6 root-cause + D-139 amendment + executable gate -- GA-R4 bookend + sweep ...

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Claude-Session: https://claude.ai/code/session_01Fg98z7QyzwYUs8fsWCn728