perf(secretary,billing): kill N+1 in secretary + claims lists (M8, M9)

M8: DoctorSecretary::toArray() lazy-loaded secretary/doctor/clinic per row;
fetch-join them in findByDoctorScope/findByClinic (shared listWithRelations()).

M9: enrichClaims() lazy-loaded each claim's items collection and called
insuranceRepo->find() per claim. Fetch-join items in findByTenant (Paginator,
fetchJoinCollection) and batch-fetch insurance names once.

Regressions (query count constant vs row count): SecretaryListNPlusOneTest,
ClaimsListNPlusOneTest.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/Billing/Repository/ClaimRepository.php

@@ -4,6 +4,7 @@ namespace App\Billing\Repository;
 
 use App\Billing\Entity\Claim;
 use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\ORM\Tools\Pagination\Paginator;
 use Doctrine\Persistence\ManagerRegistry;
 
 class ClaimRepository extends ServiceEntityRepository
@@ -24,12 +25,17 @@ class ClaimRepository extends ServiceEntityRepository
      */
     public function findByTenant(string $entityType, int $entityId, array $filters = [], int $page = 1, int $limit = 50): array
     {
-        return $this->tenantQb($entityType, $entityId, $filters)
+        // fetch-join items so enrichClaims()/toArray() don't lazy-load the
+        // items collection per claim (N+1). fetchJoinCollection keeps the LIMIT
+        // paginating by claim.
+        $qb = $this->tenantQb($entityType, $entityId, $filters)
+            ->addSelect('i')
+            ->leftJoin('c.items', 'i')
             ->orderBy('c.id', 'DESC')
             ->setFirstResult(($page - 1) * $limit)
-            ->setMaxResults($limit)
-            ->getQuery()
-            ->getResult();
+            ->setMaxResults($limit);
+
+        return iterator_to_array(new Paginator($qb, fetchJoinCollection: true));
     }
 
     public function countByTenant(string $entityType, int $entityId, array $filters = []): int