Single doc capturing the 'what's not done' at the end of the
2026-05-11 sprint, in priority order: B5 reactor boundary-conditions
merge, Phase 8 PR cycle, a handful of small open-questions follow-ups,
plus the wiki cosmetics list. README.md links to it from the top.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
