添加下拉刷新功能，优化比赛加载逻辑

app/(tabs)/index.tsx

@@ -24,6 +24,7 @@ import { useTranslation } from "react-i18next";
 import {
   ActivityIndicator,
   FlatList,
+  RefreshControl,
   StyleSheet,
   TouchableOpacity,
   View,
@@ -44,6 +45,7 @@ export default function HomeScreen() {
   const [leagues, setLeagues] = useState<League[]>([]);
   const [matches, setMatches] = useState<Match[]>([]);
   const [loading, setLoading] = useState(true);
+  const [refreshing, setRefreshing] = useState(false);
   const [loadingLeagues, setLoadingLeagues] = useState(false);
   const [now, setNow] = useState(() => new Date());
   const [liveLeagueIdByMatchId, setLiveLeagueIdByMatchId] = useState<
@@ -321,8 +323,8 @@ export default function HomeScreen() {
     }
   };
 
-  const loadMatches = async (sportId: number) => {
+  const loadMatches = async (sportId: number, isRefresh = false) => {
-    setLoading(true);
+    if (!isRefresh) setLoading(true);
     try {
       const res = await fetchTodayMatches({
         sportId,
@@ -441,10 +443,17 @@ export default function HomeScreen() {
     } catch (e) {
       console.error(e);
     } finally {
-      setLoading(false);
+      if (!isRefresh) setLoading(false);
     }
   };
 
+  const onRefresh = async () => {
+    if (!selectedSportId) return;
+    setRefreshing(true);
+    await loadMatches(selectedSportId, true);
+    setRefreshing(false);
+  };
+
   const loadMoreMatches = async () => {
     if (loadingMore || loading) return;
     if (!selectedSportId) return;
@@ -604,6 +613,9 @@ export default function HomeScreen() {
           renderItem={({ item }) => (
             <MatchCard match={item} onFavoriteToggle={handleFavoriteToggle} />
           )}
+          refreshControl={
+            <RefreshControl refreshing={refreshing} onRefresh={onRefresh} />
+          }
           onEndReached={loadMoreMatches}
           onEndReachedThreshold={0.4}
           ListFooterComponent={