Merged ahead of the v0.19.3 dossier fix so staging smoke gates it.
QA: APPROVE qa-reviews/peptide-e2e/2026-06-12-0c5c301.md (re-head after conflict resolution)
Agent-Session: cto-dossier-403-hotfix-20260612
Guards the submenu-before-parent 404 class in the deploy gate.
QA: APPROVE-W-P2 qa-reviews/peptide-e2e/2026-06-12-113bb17.md
Agent-Session: cto-board-404-hotfix-merge-20260612