20260903T2030Z open questions are issues

What. Open questions are GitHub issues labeled open-question, one per question, assigned to the decider. docs/open-questions/ (nine files: six on main, three on feat/graph-data-model) removed; each file became issue #7 to #15 with its content intact. Skill, CLAUDE.md read order, nav, conventions.md, and the scenarios index updated to point at issues. A decision closes the issue and the D-entry links it.

Why. One place for a conversation, not two (Nacho, 2026-09-03). Files cannot hold a thread or notify an owner; a file plus an issue drifts. If opening GitHub becomes a cost, the fallback is a decisions folder that stores the conversation with the entry.

Verify. gh issue list --label open-question shows nine; ls docs/open-questions fails; make docs-build exits 0.