refactor: 移除搜尋欄位內的橢圓形查詢數量顯示

- 移除搜尋框內重複的查詢結果數量顯示
- 保留清除搜尋按鈕功能
- 統一在搜尋控制下方顯示詞卡統計信息

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/app/flashcards/page.tsx

@@ -246,11 +246,6 @@ function FlashcardsContent() {
               </span>
             )}
           </h3>
-          {searchState.cacheHit && (
-            <span className="text-xs text-green-600 bg-green-50 px-2 py-1 rounded-full">
-              快取
-            </span>
-          )}
         </div>
 
         {/* Search Results */}
@@ -372,10 +367,7 @@ function SearchControls({ searchState, searchActions, showAdvancedSearch, setSho
           </svg>
         </div>
         {(searchState.filters.search || (searchState as any).hasActiveFilters) && (
-          <div className="absolute inset-y-0 right-0 pr-3 flex items-center gap-2">
+          <div className="absolute inset-y-0 right-0 pr-3 flex items-center">
-            <span className="text-xs text-gray-500 bg-blue-100 px-2 py-1 rounded-full">
-              {searchState.pagination.totalCount} 結果
-            </span>
             <button
               onClick={searchActions.clearFilters}
               className="text-gray-400 hover:text-gray-600 p-1 rounded-full hover:bg-gray-100 transition-colors"