Add backend and frontend structure with routing, components, and styling

- Implemented Express server with CORS and dotenv support
- Created basic routing with React Router in frontend
- Added Admin and Home components with navigation
- Integrated MainForm component for user input
- Updated package.json and package-lock.json with new dependencies
- Styled components using Tailwind CSS and Lucide icons
- Added error handling in server
- Created initial EJS view for backend

frontend/src/components/Header.tsx

@@ -1,9 +1,26 @@
 import React from "react";
+import { Award, RectangleEllipsis } from "lucide-react";
 
 const Header: React.FC = () => {
   return (
-    <header>
-      <h1>Header</h1>
+    <header className="w-full border-b border-black/10 bg-gray-100/95 shadow-sm">
+      <div className="mx-auto flex max-w-7xl items-center justify-between px-4 py-3 md:px-6">
+        <div className="flex items-center gap-3">
+          <Award className="h-8 w-8 text-black" strokeWidth={2.6} />
+          <h1 className="text-2xl font-black tracking-tight text-neutral-900 md:text-3xl">
+            MCS Lose
+          </h1>
+        </div>
+        <a href="/admin">
+          <button
+            type="button"
+            className="inline-flex items-center gap-2 rounded-xl border border-black/10 bg-gray-200/90 px-4 py-2 font-semibold text-neutral-900 shadow-inner transition hover:bg-gray-300/90"
+          >
+            <RectangleEllipsis className="h-5 w-5" />
+            Login
+          </button>
+        </a>
+      </div>
     </header>
   );
 };