feat: port payment management tab from tauri to admin dashboard

Add per-clinic payment methods (bank accounts + POS/card-reader devices)
under the "مدیریت پرداخت" settings tab at /admin/my-financial, ported from
clinic-pro-tauri's mock-only PaymentManagement tab into a real persisted
feature. These records are referenceable (by uuid) from patient invoices to
record which method a service payment was made with.

Backend (new src/PaymentMethod domain):
- BankAccount + Pos entities, repositories, PaymentMethodService (validation,
  ownership scoping, create/update/toggle logic).
- Thin PaymentMethodController exposing /api/v1/my/payment-methods/{bank-accounts,pos}
  (GET/POST/PUT + PATCH .../status), guarded to clinic/doctor/secretary/admin.
- Migration for bank_accounts + pos_devices tables.
- Functional tests (success + validation/404/403 + empty boundaries).
- docs/api/payment-method.md.

Frontend:
- Replace MyFinancialPage content with the payment-management UI (two tabs,
  tables, add/edit modals, status toggle) using the admin design system.
- usePaymentMethods hook (TanStack Query) + presentational components.
- Update page test to cover tabs, data, empty state and the add modal.

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

src/PaymentMethod/Repository/BankAccountRepository.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace App\PaymentMethod\Repository;
+
+use App\Auth\Entity\User;
+use App\PaymentMethod\Entity\BankAccount;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+
+class BankAccountRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, BankAccount::class);
+    }
+
+    public function findByUuid(string $uuid): ?BankAccount
+    {
+        return $this->findOneBy(['uuid' => $uuid]);
+    }
+
+    /** @return BankAccount[] */
+    public function findByUser(User $user): array
+    {
+        return $this->createQueryBuilder('b')
+            ->where('b.user = :user')->setParameter('user', $user)
+            ->orderBy('b.createdAt', 'DESC')
+            ->getQuery()
+            ->getResult();
+    }
+
+    public function save(BankAccount $entity, bool $flush = true): void
+    {
+        $this->getEntityManager()->persist($entity);
+        if ($flush) $this->getEntityManager()->flush();
+    }
+}

src/PaymentMethod/Repository/PosRepository.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace App\PaymentMethod\Repository;
+
+use App\Auth\Entity\User;
+use App\PaymentMethod\Entity\Pos;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+
+class PosRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, Pos::class);
+    }
+
+    public function findByUuid(string $uuid): ?Pos
+    {
+        return $this->findOneBy(['uuid' => $uuid]);
+    }
+
+    /** @return Pos[] */
+    public function findByUser(User $user): array
+    {
+        return $this->createQueryBuilder('p')
+            ->where('p.user = :user')->setParameter('user', $user)
+            ->orderBy('p.createdAt', 'DESC')
+            ->getQuery()
+            ->getResult();
+    }
+
+    public function save(Pos $entity, bool $flush = true): void
+    {
+        $this->getEntityManager()->persist($entity);
+        if ($flush) $this->getEntityManager()->flush();
+    }
+}