feat(subscription): add Stripe action controls

Add subscription action handling and tests for cancel, resume, and refund flows while resolving StripeClient through the container.

app/Providers/AppServiceProvider.php

@@ -11,6 +11,7 @@ use Illuminate\Support\ServiceProvider;
 use Illuminate\Validation\Rules\Password;
 use Laravel\Sanctum\Sanctum;
 use Laravel\Telescope\TelescopeServiceProvider;
+use Stripe\StripeClient;
 
 class AppServiceProvider extends ServiceProvider
 {
@@ -19,6 +20,8 @@ class AppServiceProvider extends ServiceProvider
         if (App::isLocal()) {
             $this->app->register(TelescopeServiceProvider::class);
         }
+
+        $this->app->bind(StripeClient::class, fn () => new StripeClient(config('subscription.stripe_api_key')));
     }
 
     public function boot(): void