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/(tabs)/explore.tsx

@@ -14,8 +14,8 @@ import { useAuthGuard } from '@/hooks/useAuthGuard';
 import { TrainingPlan } from '@/services/trainingPlanApi';
 import { useRouter } from 'expo-router';
 import React from 'react';
-import { Animated, Image, PanResponder, Pressable, SafeAreaView, ScrollView, StyleSheet, useWindowDimensions, View } from 'react-native';
-import { useSafeAreaInsets } from 'react-native-safe-area-context';
+import { Animated, Image, PanResponder, Pressable, ScrollView, StyleSheet, useWindowDimensions, View } from 'react-native';
+import { SafeAreaView, useSafeAreaInsets } from 'react-native-safe-area-context';
 
 // 移除旧的“热门活动”滑动数据，改为固定的“热点功能”卡片