CLOSED 2026-09-23 (claude-code, 075ddc4): ClientSecretEndDate stamped now+365d (Scope.AppPrincipals, data), expired secret refused; served appregnew returns the end date (4f13079).
ROUTINE yearly. OWNER claude-code. SharePoint client secrets expire; a People row carries no expiry date, so a leaked secret works forever until rotated by hand.