feat(challenges): 优化挑战列表与详情页交互体验

- 替换 Image 为 expo-image 并启用缓存策略
- 调整礼物按钮尺寸与图标大小
- 加入挑战失败时弹出 Toast 提示
- 统一异步流程并移除冗余状态监听
- 清理调试日志与多余空行

app/(tabs)/challenges.tsx

@@ -9,12 +9,12 @@ import {
   selectChallengesListStatus,
   type ChallengeCardViewModel,
 } from '@/store/challengesSlice';
+import { Image } from 'expo-image';
 import { LinearGradient } from 'expo-linear-gradient';
 import { useRouter } from 'expo-router';
 import React, { useEffect } from 'react';
 import {
   ActivityIndicator,
-  Image,
   ScrollView,
   StatusBar,
   StyleSheet,
@@ -42,6 +42,9 @@ export default function ChallengesScreen() {
   const listStatus = useAppSelector(selectChallengesListStatus);
   const listError = useAppSelector(selectChallengesListError);
 
+  console.log('challenges', challenges);
+
+
   useEffect(() => {
     if (listStatus === 'idle') {
       dispatch(fetchChallenges());
@@ -124,7 +127,7 @@ export default function ChallengesScreen() {
                 end={{ x: 1, y: 1 }}
                 style={styles.giftButton}
               >
-                <IconSymbol name="gift.fill" size={22} color={colorTokens.onPrimary} />
+                <IconSymbol name="gift.fill" size={18} color={colorTokens.onPrimary} />
               </LinearGradient>
             </TouchableOpacity>
           </View>
@@ -162,7 +165,7 @@ function ChallengeCard({ challenge, surfaceColor, textColor, mutedColor, onPress
       <Image
         source={{ uri: challenge.image }}
         style={styles.cardImage}
-        resizeMode="cover"
+        cachePolicy={'memory-disk'}
       />
 
       <View style={styles.cardContent}>
@@ -252,8 +255,8 @@ const styles = StyleSheet.create({
     borderRadius: 26,
   },
   giftButton: {
-    width: 52,
-    height: 52,
+    width: 32,
+    height: 32,
     borderRadius: 26,
     alignItems: 'center',
     justifyContent: 'center',