Simple Working Layout

This is a completely rebuilt, simple layout that actually works!

✅ What Works

✅ Logo positioned on left above sidebar
✅ Header dropdowns open correctly
✅ Hamburger menu toggles sidebar
✅ Sidebar submenus work
✅ Responsive design
✅ No console errors
✅ Clean, simple code

🎯 Test Features

Header Dropdowns: Click the bell, envelope, or user avatar to test dropdowns.

Sidebar Menu: Click "Components", "Tables", etc. to test submenus.

Hamburger Menu: Click the hamburger icon to toggle sidebar.

Responsive: Resize window to test mobile behavior.