Solid App Scaffolding

Create a production-grade Next.js app scaffolding with a "Frame vs. Canvas" layout architecture. Implement a fixed top navbar and fixed bottom footer that never scroll (using flex-shrink-0). The main content area should be the only scrollable region (flex-1 overflow-y-auto). Ensure the layout root uses flex-col h-screen to lock the viewport. This structure prevents "scroll chaining" and keeps navigation elements permanently accessible, similar to a native desktop application.