Refactor navigation components for improved layout and functionality

- Updated UserMenu.vue to enhance button styling and spacing for a more modern look.
- Simplified CartFAB.vue to always show the cart button when items are present, regardless of the route.
- Adjusted AppHeader.vue for better alignment of elements.
- Enhanced AreaTabs.vue to enable the educator tab and improve badge styling.
- Refined BottomNav.vue to handle cart visibility and navigation more effectively.

These changes aim to enhance user navigation and overall experience within the application.

app/components/Cart/CartFAB.vue

@@ -7,16 +7,10 @@ import { Button } from '@/components/ui/button'
 const { itemCount, total } = useCart()
 const { open } = useCartUI()
 
-// Get current route
-const route = useRoute()
-
 // Determine if FAB should be visible
 const isVisible = computed(() => {
-  // Only show on /products and /products/[id] routes
-  const isProductPage = route.path === '/products' || route.path.startsWith('/products/')
-
-  // Only show when cart has items
-  return isProductPage && itemCount.value > 0
+  // Show when cart has items (on all pages)
+  return itemCount.value > 0
 })
 
 // Format price as EUR in German locale