refactor: normalize date handling to Tehran timezone

- Updated date handling in BlogSeoFields and ScheduleSection to use Tehran timezone utilities for consistency.
- Introduced `toTehranClockTime`, `tehranWallClockToUnix`, and `todayIso` functions for accurate date representation.
- Modified various components to utilize these new utilities, ensuring that date strings are correctly formatted and timestamps are accurately converted.
- Enhanced API documentation to clarify the handling of date fields, emphasizing the importance of server-local midnight.
- Added tests to verify that date overrides and holidays maintain the correct day without shifting due to timezone discrepancies.

assets/admin/pages/AppointmentCreatePage.tsx

@@ -14,7 +14,7 @@ import { WalletChargeLink } from '../components/AppointmentActions';
 import { useDoctorBookingServices } from '../hooks/useDoctorBookingServices';
 import ServiceSlotPicker from '../components/appointments/ServiceSlotPicker';
 import { tehranWallClockToUnix, rialToToman, tomanToRial } from '../lib/utils';
-import { digitsOnly } from '../lib/utils';
+import { digitsOnly, todayIso } from '../lib/utils';
 
 /**
  * افزودن نوبت — صفحهٔ کامل (بازسازی `CreateTurn.jsx` طرح tauri). از همان endpointهای
@@ -43,7 +43,7 @@ export default function AppointmentCreatePage() {
   const dbUuid = useAuthStore(s => s.dbUuid);
   const isDoctor = primaryRole === 'doctor';
 
-  const today = new Date().toISOString().slice(0, 10);
+  const today = todayIso();
 
   // ── پزشک
   const [doctorUuid, setDoctorUuid] = useState(isDoctor && dbUuid ? dbUuid : (params.get('doctor') ?? ''));

assets/admin/pages/AppointmentsPage.tsx

@@ -9,7 +9,7 @@ import { toast } from 'sonner';
 import { api } from '../lib/api';
 import type { PaginatedResponse, ApiResponse } from '../lib/api';
 import type { Appointment } from '../types';
-import { formatDate, toGregorianDate, formatTime, digitsOnly, sanitizeMobileInput, rialToToman, tomanToRial, formatRial } from '../lib/utils';
+import { formatDate, toGregorianDate, todayIso, formatTime, digitsOnly, sanitizeMobileInput, rialToToman, tomanToRial, formatRial } from '../lib/utils';
 import PriceInput from '../components/ui/PriceInput';
 import Modal from '../components/ui/Modal';
 import { useAuthStore } from '../stores/authStore';
@@ -507,7 +507,7 @@ export default function AppointmentsPage() {
   const canCancelAppt = can('appointments', 'cancel');
 
   const [params] = useSearchParams();
-  const today = new Date().toISOString().slice(0, 10);
+  const today = todayIso();
   // پس از ویرایش/ثبت، صفحه با ?date=... باز می‌شود تا همان روز نمایش داده شود.
   const [selectedDate, setSelectedDate] = useState(params.get('date') || today);
   const [viewMode, setViewMode] = useState<TurnsViewMode>('timeline');

assets/admin/pages/ClaimsPage.tsx

@@ -3,7 +3,7 @@ import { useQuery } from '@tanstack/react-query';
 import { useNavigate, useSearchParams } from 'react-router-dom';
 import { ArrowPathIcon } from '@heroicons/react/24/outline';
 import { api } from '../lib/api';
-import { formatRial, formatNumber } from '../lib/utils';
+import { formatRial, formatNumber, toGregorianDate, todayIso } from '../lib/utils';
 import type { ClaimPatientRow } from '../types';
 import type { ApiResponse, PaginatedResponse } from '../lib/api';
 import PageHeader from '../components/ui/PageHeader';
@@ -35,9 +35,8 @@ const PAYMENT_OPTIONS = [
 const isoNDaysAgo = (days: number): string => {
   const d = new Date();
   d.setDate(d.getDate() - days);
-  return d.toISOString().slice(0, 10);
+  return toGregorianDate(d);
 };
-const todayIso = (): string => new Date().toISOString().slice(0, 10);
 
 const toUnix = (iso: string): number | null => {
   if (!iso) return null;

assets/admin/pages/MyPaymentsPage.tsx

@@ -7,7 +7,7 @@ import SearchableSelect from '../components/ui/SearchableSelect';
 import StatCard from '../components/ui/StatCard';
 import StatusBadge from '../components/ui/StatusBadge';
 import DataTable, { type Column } from '../components/ui/DataTable';
-import { formatRial, formatDate, formatNumber, toDate } from '../lib/utils';
+import { formatRial, formatDate, formatNumber, toDate, toGregorianDate, todayIso } from '../lib/utils';
 import {
   usePayments,
   usePaymentsSummary,
@@ -25,9 +25,8 @@ const STATUS_OPTIONS = [
 const isoNDaysAgo = (days: number): string => {
   const d = new Date();
   d.setDate(d.getDate() - days);
-  return d.toISOString().slice(0, 10);
+  return toGregorianDate(d);
 };
-const todayIso = (): string => new Date().toISOString().slice(0, 10);
 
 /** HH:MM (Persian digits) from a unix timestamp. */
 function formatTime(unix: number): string {

assets/admin/pages/PatientDetailPage.tsx

@@ -13,7 +13,7 @@ import { api } from '../lib/api';
 import type { ApiResponse } from '../lib/api';
 import type { PatientRecord } from '../types';
 import { useAuthStore } from '../stores/authStore';
-import { formatDate, formatDateTime, formatRial, formatTime, formatNumber } from '../lib/utils';
+import { formatDate, formatDateTime, formatRial, formatTime, formatNumber, unixToIso } from '../lib/utils';
 import DataTable, { type Column } from '../components/ui/DataTable';
 import type { WalletTxn } from '../hooks/usePatientWallet';
 import type { WalletModalSubmit } from '../components/WalletTransactionModal';
@@ -390,7 +390,7 @@ function MedicalRecordsTab({ uuid }: { uuid: string }) {
 
   const open = (m?: MedicalItem) => {
     setTitle(m?.title ?? ''); setBody(m?.body ?? '');
-    setDate(m?.recorded_at ? new Date(m.recorded_at * 1000).toISOString().slice(0, 10) : '');
+    setDate(unixToIso(m?.recorded_at));
     setModal(m ?? 'create');
   };
 

assets/admin/pages/PatientRecordFormPage.tsx

@@ -12,7 +12,7 @@ import type { PatientRecord } from '../types';
 import PersianDateInput from '../components/ui/PersianDateInput';
 import SearchableSelect from '../components/ui/SearchableSelect';
 import { numericField } from '../lib/forms';
-import { iranNationalCodeSchema, iranMobileSchema } from '../lib/utils';
+import { iranNationalCodeSchema, iranMobileSchema, unixToIso } from '../lib/utils';
 
 const REFERRAL_OPTIONS = ['اینستاگرام', 'معرفی دوستان و آشنایان', 'جستجوی اینترنتی', 'تابلو مطب', 'سایر'];
 
@@ -29,7 +29,7 @@ const schema = z.object({
 type Form = z.infer<typeof schema>;
 
 const toEpoch = (iso?: string) => (iso ? Math.floor(new Date(iso).getTime() / 1000) : null);
-const fromEpoch = (ts?: number | null) => (ts ? new Date(ts * 1000).toISOString().slice(0, 10) : '');
+const fromEpoch = (ts?: number | null) => unixToIso(ts);
 
 /** تشکیل/ویرایش پرونده — patient record create & edit form (Figma "تشکیل پرونده"). */
 export default function PatientRecordFormPage() {

assets/admin/pages/PaymentDetailPage.tsx

@@ -114,7 +114,7 @@ export default function PaymentDetailPage() {
               {payment.refunds.map((r, i) => (
                 <InfoRow
                   key={i}
-                  label={formatDateTime(new Date(r.at * 1000).toISOString())}
+                  label={formatDateTime(r.at)}
                   value={
                     <span>
                       {formatRial(r.amount)}