[Developer] #533 전체보기/내위치 토글 언급수 필터 초기화 반영

- page.tsx: 전역 '전체보기' 노출 조건에 minMentions > 0 추가, onClick에 setMinMentions(0) 추가
- 내위치 토글 ON 초기화 목록에도 setMinMentions(0) 추가 (상호배타 일관성)
- 설계서 §7 필터 리셋 일관성 명시
- tsc/jest(6 suites, 32 tests) 통과

Refs #533

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/app/page.tsx

@@ -907,7 +907,7 @@ export default function Home() {
                 )}
               </div>
               {/* 필터 전체 해제 */}
-              {(channelFilter || cuisineFilter || priceFilter || countryFilter) && (
+              {(channelFilter || cuisineFilter || priceFilter || countryFilter || minMentions > 0) && (
                 <button
                   onClick={() => {
                     setChannelFilter("");
@@ -916,6 +916,7 @@ export default function Home() {
                     setCountryFilter("");
                     setCityFilter("");
                     setDistrictFilter("");
+                    setMinMentions(0);
                     setRegionFlyTo(null);
                   }}
                   className="flex items-center gap-1 rounded-lg px-2.5 py-1.5 bg-gray-50 dark:bg-gray-800/50 text-gray-500 dark:text-gray-400 hover:text-brand-500 transition-colors touch-manipulation"
@@ -936,6 +937,7 @@ export default function Home() {
                     setCountryFilter("");
                     setCityFilter("");
                     setDistrictFilter("");
+                    setMinMentions(0);
                     if (navigator.geolocation) {
                       navigator.geolocation.getCurrentPosition(
                         (pos) => { setUserLoc({ lat: pos.coords.latitude, lng: pos.coords.longitude }); setRegionFlyTo({ lat: pos.coords.latitude, lng: pos.coords.longitude, zoom: 15 }); },