improvement: loading state added to buttons who interact with backend.

frontend/src/components/ui/appointments/AppointmentBookingModal.tsx

@@ -319,7 +319,7 @@ export function AppointmentBookingModal({
             <Button
               type="button"
               variant="danger"
-              onClick={() => void onDelete()}
+              onClick={() => onDelete()}
               disabled={loading || deleting}
               isLoading={deleting}
               fullWidth
@@ -342,7 +342,7 @@ export function AppointmentBookingModal({
             <Button
               type="button"
               variant="primary"
-              onClick={() => void handleSubmit()}
+              onClick={() => handleSubmit()}
               isLoading={loading}
               disabled={deleting}
               fullWidth