refactor(users): use unified subscription scopes in filter

- Replace manual subscription queries with dedicated User model scopes
  - Use withActiveSubscription() and withoutActiveSubscription() methods
  - Improve consistency and maintainability of subscription logic
  - Remove Stripe-specific field references for multi-provider support

app/Filament/Resources/UserResource.php

@@ -130,15 +130,9 @@ class UserResource extends Resource
                     ])
                     ->query(function ($query, array $data): void {
                         if ($data['value'] === 'subscribed') {
-                            $query->whereHas('subscriptions', function ($query): void {
-                                $query->where('stripe_status', 'active')
-                                    ->orWhere('stripe_status', 'trialing');
-                            });
+                            $query->withActiveSubscription();
                         } elseif ($data['value'] === 'not_subscribed') {
-                            $query->whereDoesntHave('subscriptions', function ($query): void {
-                                $query->where('stripe_status', 'active')
-                                    ->orWhere('stripe_status', 'trialing');
-                            });
+                            $query->withoutActiveSubscription();
                         }
                     }),
                 SelectFilter::make('email_verified')