🚚 reconstructing and fixing file structures

The reconstruction includes moving the Navbar component from shared to widget because Navbar is a group of elements, and
removing the login-signup form due to changes in logic that will use a popup flow to improve the user experience without
navigating to another page for authentication.

package.json

@@ -2,6 +2,7 @@
   "name": "frontend",
   "version": "0.1.0",
   "private": true,
+  "type": "module",
   "scripts": {
     "dev": "next dev --turbopack",
     "build": "next build",