perf(app): 添加登录状态检查并优化性能

- 在多个页面添加 isLoggedIn 检查，防止未登录时进行不必要的数据获取
- 使用 React.memo 和 useMemo 优化个人页面徽章渲染性能
- 为 badges API 添加节流机制，避免频繁请求
- 优化图片缓存策略和字符串处理
- 移除调试日志并改进推送通知的认证检查

app/(tabs)/medications.tsx

@@ -48,7 +48,7 @@ export default function MedicationsScreen() {
   const theme = (useColorScheme() ?? 'light') as 'light' | 'dark';
   const colors: ThemeColors = Colors[theme];
   const userProfile = useAppSelector((state) => state.user.profile);
-  const { ensureLoggedIn } = useAuthGuard();
+  const { ensureLoggedIn, isLoggedIn } = useAuthGuard();
   const { checkServiceAccess } = useVipService();
   const { openMembershipModal } = useMembershipModal();
   const [selectedDate, setSelectedDate] = useState<Dayjs>(dayjs());
@@ -144,9 +144,11 @@ export default function MedicationsScreen() {
 
   // 加载药物和记录数据
   useEffect(() => {
+    if (!isLoggedIn) return;
+
     dispatch(fetchMedications());
     dispatch(fetchMedicationRecords({ date: selectedKey }));
-  }, [dispatch, selectedKey]);
+  }, [dispatch, selectedKey, isLoggedIn]);
 
   useEffect(() => {
     return () => {
@@ -159,6 +161,8 @@ export default function MedicationsScreen() {
   // 页面聚焦时刷新数据，确保从添加页面返回时能看到最新数据
   useFocusEffect(
     useCallback(() => {
+      if (!isLoggedIn) return;
+
       // 重新安排药品通知并刷新数据
       const refreshDataAndRescheduleNotifications = async () => {
         try {
@@ -188,7 +192,7 @@ export default function MedicationsScreen() {
       };
       
       refreshDataAndRescheduleNotifications();
-    }, [dispatch, selectedKey])
+    }, [dispatch, selectedKey, isLoggedIn])
   );
 
   useEffect(() => {