Initial commit of the Asset Management System, including project structure, Docker configuration, database migrations, and core application files. Added user authentication, asset management features, and basic UI components.

app/Middleware/AdminMiddleware.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Middleware;
+
+use App\Core\Request;
+use App\Core\Response;
+use App\Core\Session;
+
+class AdminMiddleware
+{
+    public function handle(Request $request, Response $response): void
+    {
+        $session = new Session();
+        
+        // First check if user is logged in
+        if (!$session->isLoggedIn()) {
+            $session->flash('error', 'Bitte melden Sie sich an, um fortzufahren.');
+            $response->redirect('/login')->send();
+        }
+
+        // Check if user has admin role
+        if (!$session->isAdmin()) {
+            $session->flash('error', 'Sie haben keine Berechtigung für diese Aktion.');
+            $response->redirect('/dashboard')->send();
+        }
+    }
+}