feat(clients): align client form with first and last name API fields

src/app/(modules)/clients/hooks/useClientMutations.ts

@@ -20,7 +20,8 @@ export function useSaveClientMutation({ onSaved }: { onSaved: () => void }) {
     mutationFn: (values: ClientFormValues) =>
       clientService.saveClient({
         id: values.id,
-        name: values.name.trim(),
+        first_name: values.first_name.trim(),
+        last_name: values.last_name.trim(),
         email: values.email.trim(),
         landline_number: values.landline_number.trim(),
         address: values.address.trim(),