feat: hide search input when list is empty and add animated city selector highlight

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/pages/Sight/SightListPage/index.tsx

@@ -182,7 +182,9 @@ export const SightListPage = observer(() => {
           </div>
         )}
 
-        <SearchInput value={searchQuery} onChange={setSearchQuery} />
+        {rows.length > 0 && (
+          <SearchInput value={searchQuery} onChange={setSearchQuery} />
+        )}
 
         <DataGrid
           rows={rows}