feat: unify doctor title handling and enhance specialty selection

- Implemented a helper function `displayDoctorName` to prepend "دکتر" to doctor names for consistent display across the application.
- Updated various components (InviteDoctorModal, DashboardPage, DoctorDetailPage, DoctorsPage, etc.) to utilize the new helper for rendering doctor names.
- Modified the DoctorFormPage to automatically add the "دکتر" title in the UI without requiring user input.
- Fixed the EditSpecialtyPicker component to allow multiple specialty selections, resolving a UI bug where only one specialty could be selected at a time.
- Ensured that the backend strips the "دکتر" title from the name during pre-registration and doctor creation processes.
- Added tests for the new functionality, including checks for title handling and specialty selection logic.
- Updated API documentation to reflect changes in name handling and display logic.

assets/admin/lib/utils.ts

@@ -98,6 +98,15 @@ export function unixToIso(ts: number | null | undefined): string {
   return toGregorianDate(new Date(ts * 1000));
 }
 
+// عنوان «دکتر» فقط در نمایش افزوده می‌شود و هرگز در فیلد name دیتابیس ذخیره نمی‌شود
+// (backend با stripDoctorTitle حذف می‌کند). این helper تنها نقطهٔ افزودن عنوان است تا
+// در کل پنل یکسان باشد و از «دکتر دکتر …» یا نمایش بدون عنوان جلوگیری شود.
+export function displayDoctorName(name?: string | null): string {
+  const n = (name ?? '').trim();
+  if (!n) return '';
+  return n.startsWith('دکتر') ? n : `دکتر ${n}`;
+}
+
 export function maskMobile(mobile: string): string {
   if (mobile.length < 7) return mobile;
   return mobile.slice(0, 4) + '***' + mobile.slice(-3);