add: full multi-tenancy control

app/Http/Middleware/SuperAdminMiddleware.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use Closure;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Auth;
+
+class SuperAdminMiddleware
+{
+    public function handle(Request $request, Closure $next)
+    {
+        if (Auth::check() && Auth::user()->email === 'admin@example.com') {
+            return $next($request);
+        }
+
+        return redirect()->route('super-admin.session.create');
+    }
+}