fix(patient): consistent debt/paid status, invoice totals, global service search

- patient_debt_rials now = session remaining (final - discount - paid), so the
  card status and invoice status stay consistent with is_paid even after a
  session is edited post-invoicing (no more '0 remaining but تکمیل پرداخت').
- InvoiceSummaryModal: remaining subtracts discount; the فاکتور status reflects
  actual settlement (تسویه شده / بدهکار), and the payments table shows a
  «مجموع پرداختی‌ها» total row.
- Add GET /api/v1/service-items (all owner services) and make the service
  picker searchable across all services without first choosing a section.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/ClinicService/Repository/ServiceItemRepository.php

@@ -29,6 +29,18 @@ class ServiceItemRepository extends ServiceEntityRepository
             ->getResult();
     }
 
+    /** همه‌ی سرویس‌های یک owner (در همه‌ی بخش‌ها) — برای انتخاب/جستجوی سراسری. */
+    public function findByEntity(string $entityType, int $entityId): array
+    {
+        return $this->createQueryBuilder('i')
+            ->join('i.section', 's')
+            ->where('s.entityType = :type')->setParameter('type', $entityType)
+            ->andWhere('s.entityId = :id')->setParameter('id', $entityId)
+            ->orderBy('i.name', 'ASC')
+            ->getQuery()
+            ->getResult();
+    }
+
     /**
      * Count services per section in a single query (avoids N+1 in the section list).
      *