Abo Einmalprodukte: Phase 4 - Ausfuehrung, Purge & User-Retry

- UserMakeOrder: bestaetigte Einmal-Artikel in den Yard, is_abo_addon
  auf ShoppingOrderItem; amount bleibt reiner Abo-Betrag (Reihenfolge)
- AboOneTimeService::purgeAfterExecution: loescht alle Einmal-Artikel
  und rechnet Comp-Produkte neu - nur im Erfolgszweig (Cron + Retry)
- User-Retry in Sales Center und Portal mit Berechtigungspruefung,
  gemeinsames Confirm-Modal; Admin-Retry unveraendert
- Tests: AboMakeOrderOneTimeTest, AboUserRetryTest; Plan-Doku Phase 4

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Http/Controllers/Portal/AboController.php

@@ -15,6 +15,7 @@ use App\Services\AboHelper;
 use App\Services\AboItemHistoryService;
 use App\Services\AboOneTimeService;
 use App\Services\AboOrderCart;
+use App\Services\AboRetryPaymentService;
 use App\Services\Shop;
 use App\Services\UserService;
 use App\Services\Util;
@@ -491,6 +492,18 @@ class AboController extends Controller
         return false;
     }
 
+    public function retryPayment($id, AboRetryPaymentService $retryPaymentService)
+    {
+        $user_abo = UserAbo::findOrFail($id);
+        $this->checkPortalPermission($user_abo);
+
+        $result = $retryPaymentService->retry($user_abo);
+
+        \Session()->flash($result['success'] ? 'alert-success' : 'alert-error', $result['message']);
+
+        return redirect(route('portal.my_subscriptions'));
+    }
+
     private function checkPortalPermission($user_abo)
     {
         $user = Auth::guard('customers')->user();