[Developer] #545 해외 식당 테이블링/캐치테이블 버튼 숨김

- RestaurantDetail.tsx 예약 버튼 2종을 isKoreaRestaurant() 게이트로 감쌈
- 테이블링/캐치테이블은 국내 전용 — 지도 링크와 동일 판정 기준 적용

Refs #545
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/components/RestaurantDetail.tsx

@@ -181,7 +181,7 @@ export default function RestaurantDetail({
         )}
       </div>
 
-      {restaurant.tabling_url && restaurant.tabling_url !== "NONE" && (
+      {isKoreaRestaurant(restaurant) && restaurant.tabling_url && restaurant.tabling_url !== "NONE" && (
         <a
           href={restaurant.tabling_url}
           target="_blank"
@@ -193,7 +193,7 @@ export default function RestaurantDetail({
         </a>
       )}
 
-      {restaurant.catchtable_url && restaurant.catchtable_url !== "NONE" && (
+      {isKoreaRestaurant(restaurant) && restaurant.catchtable_url && restaurant.catchtable_url !== "NONE" && (
         <a
           href={restaurant.catchtable_url}
           target="_blank"