feat(service): detach/attach service to customer with activity log

- Customer tab "delete" no longer deletes the service: it detaches the
  customer, discards the order/invoices and logs a `detached` activity
  with the previous customer and order.
- New POST customers/{uuid}/services/attach assigns an unassigned
  service (GET services?unassigned=1) to a customer, creating a pending
  order + unpaid invoice when missing, and logs `attached`.
- Detach/attach also sync module_vmware/module_hosting_accounts
  customer_id: ResolvesVm authorises by module_vmware.customer_id, so a
  detached customer could still control the VM.
- /services detach-customer (single + bulk) go through the same path.
- GET services/{id} returns the service activity logs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Http/Controllers/Api/Admin/Customer/Concerns/ManagesCustomerServices.php

@@ -14,13 +14,22 @@ trait ManagesCustomerServices
         return response()->json(['error' => false, 'data' => $this->serviceProvisioning->getServices($uuid)]);
     }
 
+    public function attachService(string $uuid, Request $request): JsonResponse
+    {
+        $data = $request->validate(['service_id' => 'required|integer|exists:services,id']);
+
+        $service = $this->serviceProvisioning->attachService($uuid, $data['service_id']);
+
+        return response()->json(['error' => false, 'message' => 'Đã gán dịch vụ cho khách hàng', 'data' => $service]);
+    }
+
     public function bulkDeleteServices(string $uuid, Request $request): JsonResponse
     {
         $data = $request->validate(['ids' => 'required|array|min:1', 'ids.*' => 'integer']);
 
         $deleted = $this->serviceProvisioning->bulkDeleteServices($uuid, $data['ids']);
 
-        return response()->json(['error' => false, 'message' => "Đã xoá {$deleted} dịch vụ", 'data' => ['deleted' => $deleted]]);
+        return response()->json(['error' => false, 'message' => "Đã gỡ {$deleted} dịch vụ khỏi khách hàng", 'data' => ['deleted' => $deleted]]);
     }
 
     public function updateService(string $uuid, int $serviceId, Request $request): JsonResponse