feat: 优化图片加载和展示功能

- 新增 SmartImage 组件优化图片加载体验
- 新增 ImageGrid 组件支持多图布局展示
- 新增 imageHelper 工具函数
- 优化 PostCard 帖子卡片图片展示
- 优化消息页面 SegmentRenderer
- 优化日程页面 ScheduleScreen
- 优化上传服务 uploadService

src/screens/schedule/ScheduleScreen.tsx

@@ -145,6 +145,8 @@ export const ScheduleScreen: React.FC = () => {
   const [startWeekInput, setStartWeekInput] = useState(String(currentWeek));
   const [endWeekInput, setEndWeekInput] = useState(String(TOTAL_WEEKS));
   const weekScrollRef = useRef<ScrollView | null>(null);
+  // 组件卸载状态标记，用于防止组件卸载后仍调用 setState
+  const isMountedRef = useRef(true);
 
   // 设置弹窗状态
   const [isSettingsModalVisible, setIsSettingsModalVisible] = useState(false);
@@ -153,6 +155,13 @@ export const ScheduleScreen: React.FC = () => {
   const [syncUsername, setSyncUsername] = useState('');
   const [syncPassword, setSyncPassword] = useState('');
   const [isSyncing, setIsSyncing] = useState(false);
+
+  // 组件卸载时设置标记
+  useEffect(() => {
+    return () => {
+      isMountedRef.current = false;
+    };
+  }, []);
   const todayColumnIndex = getTodayColumnIndex();
   // currentWeek === 1 对应今天所在的真实周（offset 0），其他周不高亮今日列
   const isViewingCurrentWeek = currentWeek === 1;
@@ -463,14 +472,31 @@ export const ScheduleScreen: React.FC = () => {
                 style: 'destructive' as const,
                 onPress: async () => {
                   try {
-                    // 删除所有相关课程
-                    for (const relatedCourse of relatedCourses) {
-                      await scheduleService.deleteCourse(relatedCourse.id);
+                    // 使用 Promise.allSettled 批量删除，即使部分失败也能继续
+                    const results = await Promise.allSettled(
+                      relatedCourses.map(course => scheduleService.deleteCourse(course.id))
+                    );
+                    
+                    // 统计成功和失败的数量
+                    const fulfilledCount = results.filter(r => r.status === 'fulfilled').length;
+                    const rejectedCount = results.filter(r => r.status === 'rejected').length;
+                    
+                    // 只移除成功删除的课程
+                    const successfullyDeletedIds = new Set(
+                      relatedCourses
+                        .filter((_, index) => results[index].status === 'fulfilled')
+                        .map(c => c.id)
+                    );
+                    setCourses(prev => prev.filter(c => !successfullyDeletedIds.has(c.id)));
+                    
+                    if (rejectedCount > 0) {
+                      Alert.alert(
+                        '部分删除成功',
+                        `成功删除 ${fulfilledCount} 节课程，${rejectedCount} 节删除失败，请重试`
+                      );
+                    } else {
+                      Alert.alert('成功', `已删除 ${fulfilledCount} 节课程`);
                     }
-                    // 从本地状态中移除
-                    const relatedIds = new Set(relatedCourses.map(c => c.id));
-                    setCourses(prev => prev.filter(c => !relatedIds.has(c.id)));
-                    Alert.alert('成功', `已删除 ${relatedCourses.length} 节课程`);
                   } catch (error) {
                     console.error('批量删除课程失败:', error);
                     Alert.alert('删除失败', '请稍后重试');
@@ -755,14 +781,17 @@ export const ScheduleScreen: React.FC = () => {
                 ]}
                 onPress={async () => {
                   if (!syncUsername.trim() || !syncPassword.trim()) return;
-
+  
                   setIsSyncing(true);
                   try {
                     const result = await scheduleService.syncSchedule({
                       username: syncUsername.trim(),
                       password: syncPassword.trim(),
                     });
-
+  
+                    // 检查组件是否已卸载
+                    if (!isMountedRef.current) return;
+  
                     if (result.success) {
                       Alert.alert(
                         '同步成功',
@@ -787,9 +816,15 @@ export const ScheduleScreen: React.FC = () => {
                     }
                   } catch (error) {
                     console.error('同步课表失败:', error);
-                    Alert.alert('同步失败', '网络错误，请稍后重试');
+                    // 检查组件是否已卸载
+                    if (isMountedRef.current) {
+                      Alert.alert('同步失败', '网络错误，请稍后重试');
+                    }
                   } finally {
-                    setIsSyncing(false);
+                    // 检查组件是否已卸载
+                    if (isMountedRef.current) {
+                      setIsSyncing(false);
+                    }
                   }
                 }}
                 activeOpacity={0.8}