feat: 更新多个组件以使用 SafeAreaView

- 在 goals-list、task-list、explore、personal、challenge/day 和 challenge/index 组件中引入 SafeAreaView，确保内容在安全区域内显示
- 移除不必要的 SafeAreaView 导入，优化代码结构
- 更新相关样式，提升用户体验和界面一致性

app/task-list.tsx

@@ -12,7 +12,8 @@ import dayjs from 'dayjs';
 import { LinearGradient } from 'expo-linear-gradient';
 import { useRouter } from 'expo-router';
 import React, { useCallback, useEffect, useMemo, useState } from 'react';
-import { Alert, FlatList, RefreshControl, SafeAreaView, StatusBar, StyleSheet, Text, View } from 'react-native';
+import { Alert, FlatList, RefreshControl, StatusBar, StyleSheet, Text, View } from 'react-native';
+import { SafeAreaView } from 'react-native-safe-area-context';
 
 export default function GoalsDetailScreen() {
   const theme = (useColorScheme() ?? 'light') as 'light' | 'dark';