MainLayout was rendered inside each page component, causing the entire
layout (sidebar, mobile nav, drawer) to be destroyed and recreated on
every route change. This made navigations feel like full page refreshes.
Restructured to use a React Router layout route with <Outlet />, so
MainLayout persists across navigations and only the page content swaps.
Pages that need custom layout options (showFAB, rightSidebar, etc.) use
the new useLayoutOptions hook to configure the persistent layout.
Alex Gleason
3daf38c9fd