feat: update models and relationships

app/Models/Flight.php

@@ -9,6 +9,8 @@ namespace App\Models;
 use App\Enums\FlightStatus;
 use App\Enums\FlightTripType;
 use Carbon\Carbon;
+use Illuminate\Database\Eloquent\Attributes\Scope;
+use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Database\Eloquent\Model;
 
@@ -65,6 +67,28 @@ class Flight extends Model
         'status',
         'trip_type'
     ];
+    #[Scope]
+    protected function applySort(Builder $query): void
+    {
+        switch (request()->input('sort')) {
+            case 'popularity':
+                $query->withCount('bookings')
+                    ->orderByDesc('bookings_count');
+                break;
+
+            case 'lowest':
+                $query->orderBy('price');
+                break;
+
+            case 'highest':
+                $query->orderByDesc('price');
+                break;
+
+            default:
+                $query->latest('id'); // همه‌ی پروازها
+                break;
+        }
+    }
 
     public function airline()
     {