fix: derive contingent change signal from the sync diff

src/Repository/Groups/ContingentDayRepository.php

@@ -71,30 +71,6 @@ class ContingentDayRepository extends ServiceEntityRepository
         return $this->indexByDate($days);
     }
 
-    /**
-     * Returns the accommodation's complete stored snapshot as an ordered "Y-m-d:STATUS" list.
-     *
-     * Scalar hydration keeps the fingerprint cheap: the entities themselves are of no interest here.
-     *
-     * @return list<string>
-     */
-    public function findStatusFingerprintParts(Accommodation $accommodation): array
-    {
-        /** @var array<int, array{date: \DateTimeImmutable, status: \App\BpnConnect\Model\ContingentStatus}> $rows */
-        $rows = $this->createQueryBuilder('cd')
-            ->select('cd.date', 'cd.status')
-            ->where('cd.accommodation = :accommodation')
-            ->setParameter('accommodation', $accommodation)
-            ->orderBy('cd.date', 'ASC')
-            ->getQuery()
-            ->getArrayResult();
-
-        return array_map(
-            static fn (array $row) => $row['date']->format('Y-m-d').':'.$row['status']->value,
-            $rows,
-        );
-    }
-
     /**
      * Retention: drops snapshot days that are in the past and can no longer be requested.
      */