No loading.tsx anywhere — route transitions show a blank main until client effects resolve

[Jose-Gael-Cruz-Lopez]

Severity: Low
Labels: tech-debt, frontend, P3
Location: frontend/src/app/ (no loading.tsx files)

Description

There are zero loading.tsx files. The (shell) layout is a client component and every page fetches client-side, so data-heavy routes (dashboard, gradebook, knowledge graph) show a blank <main> until client effects resolve, instead of an instant skeleton via the App Router's Suspense integration.

Suggested fix

Add loading.tsx to (shell)/ (reusing the existing Skeleton/ProfileSkeleton) and any server-rendered segment.

Acceptance criteria

• Navigating to shell routes paints a skeleton immediately rather than a blank panel.