fix: prevent generating offer links while booking is in draft

tests/Entity/Groups/AccommodationBookingTest.php

@@ -72,6 +72,23 @@ class AccommodationBookingTest extends TestCase
         self::assertSame('Buchung', $accepted->recordLabel());
     }
 
+    public function testADraftIsTheOnlyStatusTheCustomerMustNotReach(): void
+    {
+        // Entwurf is the office's own workbench — nothing has been offered yet, so there is
+        // nothing an access link could show. Whether a link that exists still opens anything
+        // is a separate question the offer page answers (a discarded booking does not).
+        foreach (AccommodationBookingStatus::cases() as $status) {
+            $booking = new AccommodationBooking();
+            $booking->setStatus($status);
+
+            self::assertSame(
+                AccommodationBookingStatus::Draft !== $status,
+                $booking->isCustomerAccessible(),
+                $status->value,
+            );
+        }
+    }
+
     public function testTheLabelIsIndependentOfWhereTheBookingCameFrom(): void
     {
         // Origin answers "how did this come about" and is deliberately not the same