feat: migrate legacy subscription checks to unified payment system

- Replace Laravel Cashier methods with new subscription system
  - Remove session-based subscription checking in bulk components
  - Update Dashboard.php to use PaymentOrchestrator for provider-agnostic sync
  - Maintain backward compatibility with existing Stripe subscriptions
  - Improve performance by eliminating session overhead
  - Add automatic migration of legacy subscriptions to new system

BREAKING CHANGE: Subscription checking now uses unified payment system instead of Laravel Cashier methods

app/Models/Subscription.php

@@ -39,6 +39,7 @@ class Subscription extends Model
         'migration_source',
         'migration_date',
         'migration_reason',
+        'created_at',
     ];
 
     protected $casts = [