The file that opens before the first commit April 30, 2026, late afternoon. Rembrandt's /admin page has just betrayed me for the third time in two days. Blandine, an administrator, can't see the Attendance tab even though the "Attendance" checkbox is ticked in the rights grid she manages herself. Thirty minutes of digging earlier, I'd understood: the checkbox writes to dashboard_cards (display preference) and never touches can_access_emargement (the actual permission flag). Two semantic layers stacked in the same grid, treated as one. Niran is in the room, hood loose at his back, a folded burger wrapper on the corner of his laptop. He's working on a financial analysis for Antoine, not watching my screen. I'm about to open app/admin/page.tsx and patch. Instead, I create an empty file: docs/adr/0040-admin-rbac-vs-dashboard-cards.md . Not a single line of code touched. A Markdown page.…