Two-tier navigation with dropdown profile menu

This creates a two-tier navigation layout with a top navbar and sidebar menu for mobile. The top navbar has left branding, navigation links, and a profile dropdown menu on the right. The sidebar menu slides in from the left on mobile. The top navbar is fixed and uses `bg-gray-800` with `text-white` links. The current page link gets `bg-gray-900` for indication. Links have hover states. The profile menu button triggers a dropdown with user details, settings, and logout links. The mobile menu button toggles the sidebar navigation pane. This has branding, nav links, user profile and settings.