feat: 优化目标创建成功提示及任务筛选功能

- 将目标创建成功后的提示从系统默认的 Alert.alert 改为使用自定义确认弹窗，提升用户体验和视觉一致性
- 在任务筛选中新增“已跳过”选项，支持用户更好地管理任务状态
- 更新任务卡片和进度卡片，展示跳过任务的数量和状态
- 调整相关组件样式，确保界面一致性和美观性
- 编写相关文档，详细描述新功能和使用方法

app/(tabs)/goals.tsx

@@ -2,7 +2,9 @@ import CreateGoalModal from '@/components/CreateGoalModal';
 import { TaskCard } from '@/components/TaskCard';
 import { TaskFilterTabs, TaskFilterType } from '@/components/TaskFilterTabs';
 import { TaskProgressCard } from '@/components/TaskProgressCard';
+import { useGlobalDialog } from '@/components/ui/DialogProvider';
 import { Colors } from '@/constants/Colors';
+import { TAB_BAR_BOTTOM_OFFSET, TAB_BAR_HEIGHT } from '@/constants/TabBar';
 import { useAppDispatch, useAppSelector } from '@/hooks/redux';
 import { useColorScheme } from '@/hooks/useColorScheme';
 import { clearErrors, createGoal } from '@/store/goalsSlice';
@@ -21,6 +23,7 @@ export default function GoalsScreen() {
   const colorTokens = Colors[theme];
   const dispatch = useAppDispatch();
   const router = useRouter();
+  const { showConfirm } = useGlobalDialog();
 
   // Redux状态
   const {
@@ -42,6 +45,7 @@ export default function GoalsScreen() {
   const [showCreateModal, setShowCreateModal] = useState(false);
   const [refreshing, setRefreshing] = useState(false);
   const [selectedFilter, setSelectedFilter] = useState<TaskFilterType>('all');
+  const [modalKey, setModalKey] = useState(0); // 用于强制重新渲染弹窗
 
   // 页面聚焦时重新加载数据
   useFocusEffect(
@@ -109,12 +113,34 @@ export default function GoalsScreen() {
     }
   }, [tasksError, createError, completeError, skipError, dispatch]);
 
+  // 重置弹窗表单数据
+  const handleModalSuccess = () => {
+    // 不需要在这里改变 modalKey，因为弹窗已经关闭了
+    // 下次打开时会自动使用新的 modalKey
+  };
+
   // 创建目标处理函数
   const handleCreateGoal = async (goalData: CreateGoalRequest) => {
     try {
       await dispatch(createGoal(goalData)).unwrap();
       setShowCreateModal(false);
-      Alert.alert('成功', '目标创建成功！');
+      
+      // 使用确认弹窗显示成功消息
+      showConfirm(
+        {
+          title: '目标创建成功',
+          message: '恭喜！您的目标已成功创建。系统将自动生成相应的任务，帮助您实现目标。',
+          confirmText: '确定',
+          cancelText: '',
+          icon: 'checkmark-circle',
+          iconColor: '#10B981',
+        },
+        () => {
+          // 用户点击确定后的回调
+          console.log('用户确认了目标创建成功');
+        }
+      );
+      
       // 创建目标后重新加载任务列表
       loadTasks();
     } catch (error) {
@@ -134,6 +160,7 @@ export default function GoalsScreen() {
     all: tasks.length,
     pending: tasks.filter(task => task.status === 'pending').length,
     completed: tasks.filter(task => task.status === 'completed').length,
+    skipped: tasks.filter(task => task.status === 'skipped').length,
   };
 
   // 根据筛选条件过滤任务
@@ -143,6 +170,8 @@ export default function GoalsScreen() {
         return tasks.filter(task => task.status === 'pending');
       case 'completed':
         return tasks.filter(task => task.status === 'completed');
+      case 'skipped':
+        return tasks.filter(task => task.status === 'skipped');
       default:
         return tasks;
     }
@@ -171,6 +200,9 @@ export default function GoalsScreen() {
     } else if (selectedFilter === 'completed') {
       title = '暂无已完成的任务';
       subtitle = '完成一些任务后，它们会显示在这里';
+    } else if (selectedFilter === 'skipped') {
+      title = '暂无已跳过的任务';
+      subtitle = '跳过一些任务后，它们会显示在这里';
     }
     
     return (
@@ -262,7 +294,10 @@ export default function GoalsScreen() {
                 </TouchableOpacity>
                 <TouchableOpacity
                   style={[styles.cardAddButton, { backgroundColor: colorTokens.primary }]}
-                  onPress={() => setShowCreateModal(true)}
+                  onPress={() => {
+                    setModalKey(prev => prev + 1); // 每次打开弹窗时使用新的 key
+                    setShowCreateModal(true);
+                  }}
                 >
                   <Text style={styles.cardAddButtonText}>+</Text>
                 </TouchableOpacity>
@@ -303,9 +338,11 @@ export default function GoalsScreen() {
 
         {/* 创建目标弹窗 */}
         <CreateGoalModal
+          key={modalKey}
           visible={showCreateModal}
           onClose={() => setShowCreateModal(false)}
           onSubmit={handleCreateGoal}
+          onSuccess={handleModalSuccess}
           loading={createLoading}
         />
       </View>
@@ -415,7 +452,7 @@ const styles = StyleSheet.create({
   taskList: {
     paddingHorizontal: 20,
     paddingTop: 20,
-    paddingBottom: 20,
+    paddingBottom: TAB_BAR_HEIGHT + TAB_BAR_BOTTOM_OFFSET + 20, // 避让底部导航栏 + 额外间距
   },
   emptyState: {
     alignItems: 'center',