fix namespace and use spelling mistake

apps/backend/app/Models/User.php

@@ -1,9 +1,9 @@
 <?php
 
-namespace app\Models;
+namespace App\Models;
 
 // use Illuminate\Contracts\Auth\MustVerifyEmail;
-use database\factories\UserFactory;
+use Database\Factories\UserFactory;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Foundation\Auth\User as Authenticatable;
 use Illuminate\Notifications\Notifiable;