Moves the drawer (open/close/render + getDrawerCoreFields + selectItemForDrawer) out of vault.ts into vault-drawer.ts, taking the VaultController ctx. Adds ensureDrawerClosedForRoute(state, route) — called in renderPane before the view switch — so drawer state cannot leak across navigation to non-list/detail routes (P2 safety net). New drawer-state.test.ts covers it (TDD). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>