feat(billing): patient payments list + patient invoices detail (doctor/clinic)

Port two nobat724 Figma screens into the admin SPA for the doctor/clinic
tenant panel:

- node 1 — لیست پرداخت‌ها (/admin/my-payments): per-patient payment summary
  (invoice count, paid, remaining, derived status paid/unsettled/unpaid),
  filters by national code / status / Jalali date range, pagination.
- node 2 — پرداخت‌های ثبت‌شده (/admin/my-payments/:patientUuid): a patient's
  recorded invoices with patient header, service title, total, status badge,
  and an expandable per-invoice item breakdown.

Backend (App\Billing):
- InvoiceRepository::patientPaymentSummary/countPatientPaymentSummary — DQL
  aggregation grouped by patient record (arbitrary join Invoice→PatientRecord
  →User), draft/void excluded, derived-status HAVING filters.
- InvoiceRepository::invoicesForPatient/count + InvoiceService methods that
  shape rows and derive status.
- BillingController: GET /api/v1/my/billing/patient-payments and
  GET /api/v1/my/billing/patients/{patientUuid}/invoices (thin, resolveEntity,
  tenant-scoped, 403/404). Invoice::getIssuedAt / InvoiceItem::getTitle added.
- docs/api/billing.md documents both endpoints.

Frontend: useMyPayments hooks, MyPaymentsPage, MyPaymentDetailPage, routes in
App.tsx (doctor/secretary/clinic, blockClinicScope) and a sidebar entry.
Persian strings hardcoded per existing admin convention (no i18n infra).

Tests: tests/Billing/PatientPaymentsTest.php (8), useMyPayments + both page
tests (11). Note: pre-existing LoginPage.test failures are unrelated (proven
by stashing this change).

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

assets/admin/components/layout/Sidebar.tsx

@@ -213,6 +213,11 @@ function buildSections(
                         label: "پرونده بیماران",
                         feature: "patient_records",
                     },
+                    {
+                        to: "/admin/my-payments",
+                        icon: CreditCardIcon,
+                        label: "پرداخت‌ها",
+                    },
                     {
                         to: "/admin/claims",
                         icon: DocumentTextIcon,
@@ -278,6 +283,11 @@ function buildSections(
                         label: "پرونده بیماران",
                         feature: "patient_records",
                     },
+                    {
+                        to: "/admin/my-payments",
+                        icon: CreditCardIcon,
+                        label: "پرداخت‌ها",
+                    },
                     {
                         to: "/admin/claims",
                         icon: DocumentTextIcon,
@@ -338,6 +348,11 @@ function buildSections(
                         label: "پرونده بیماران",
                         feature: "patient_records",
                     },
+                    {
+                        to: "/admin/my-payments",
+                        icon: CreditCardIcon,
+                        label: "پرداخت‌ها",
+                    },
                     {
                         to: "/admin/insurance-pricing",
                         icon: ShieldCheckIcon,