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/components/ui/InviteDoctorModal.tsx

@@ -56,7 +56,7 @@ export default function InviteDoctorModal({ clinicUuid, onClose, onInvited }: Pr
             </div>
             <div>
               <label style={{ fontSize: 13, fontWeight: 600, display: 'block', marginBottom: 6 }}>نام پزشک (اختیاری)</label>
-              <input className="input" placeholder="دکتر نام و نام خانوادگی" {...register('name')} />
+              <input className="input" placeholder="نام و نام خانوادگی" {...register('name')} />
             </div>
             <div>
               <label style={{ fontSize: 13, fontWeight: 600, display: 'block', marginBottom: 6 }}>تخصص (اختیاری)</label>