Share the sidebar page shell between the admin and settings layouts, and group the secret props on SchemaFields. SidebarLayout in src/shared renders the sidebar beside the current section, taking the sidebar's contents as its nav, so AdminLayout and SettingsLayout hold only their own links. SchemaFields takes one optional secrets prop in place of secretFields, secretsSet, cleared, and onClear, with the cleared list and its handler together under clearing, so a form cannot offer clearing without both.