feat: Implement admin role and permission management, employee management APIs, and user profile extensions.

app/Http/Middleware/CheckPermission.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use Closure;
+use Illuminate\Http\Request;
+
+class CheckPermission
+{
+    public function handle(Request $request, Closure $next, string $permission): mixed
+    {
+        $user = auth('admin')->user();
+
+        if (!$user) {
+            return response()->json([
+                'error'   => true,
+                'message' => 'Vui lòng đăng nhập để thực hiện!',
+            ], 401);
+        }
+
+        // Full Administrator luôn có tất cả quyền
+        if ($user->hasRole('Full Administrator')) {
+            return $next($request);
+        }
+
+        if (!$user->hasPermissionTo($permission)) {
+            return response()->json([
+                'error'   => true,
+                'message' => "Bạn không có quyền: \"{$permission}\".",
+            ], 403);
+        }
+
+        return $next($request);
+    }
+}