feat(nav): redesign navigation bar and add Browse/Community links

Enhance the navigation with a modern floating glass design, new Browse and Community dropdown links, and improved theme/blur toggles that now handle multiple instances. Update dropdown components with rounded styling and support for wider widths, refine nav-link active states, and add navigation feature tests.

resources/views/layouts/app.blade.php

@@ -9,7 +9,7 @@
 
         <!-- Page Heading -->
         @if (isset($header))
-            <header class="bg-white dark:bg-neutral-950/50 backdrop-blur-lg shadow mt-[65px] z-10">
+            <header class="bg-white dark:bg-neutral-950/50 backdrop-blur-lg shadow mt-[80px] z-10">
                 <div class="max-w-7xl mx-auto py-6 px-4 sm:px-6 lg:px-8">
                     {{ $header }}
                 </div>
@@ -17,7 +17,7 @@
         @endif
 
         <!-- Page Content -->
-        <div @if (!isset($header)) class="mt-[65px]" @else class="mt-[40px]" @endif>
+        <div @if (!isset($header)) class="mt-[80px]" @else class="mt-[40px]" @endif>
             <main>
                 {{ $slot }}
             </main>