Root cause: useDashboardLayout initialised React state with createDefaultDashboardLayout()
(1 widget), so the wrong default rendered during the ~100–500ms window while React Query
fetched the user session and DB layout after login. On reload within staleTime the cache
hit resolved instantly, masking the bug.
Fix: add isHydrated boolean state that becomes true only once localStorage OR DB
hydration has settled; DashboardClient renders a GridLayoutSkeleton until then.
Also adds router.refresh() in the sign-in handler to bust the Next.js Router Cache
so the post-login navigation always lands on a fresh server component tree.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Hartmut
a16c41e739