feat(challenges): 登录态守卫与进度条动画优化

- 在 _layout 中仅当已登录时才拉取挑战列表，避免未授权请求
- 挑战详情页加入 ensureLoggedIn 守卫，未登录时跳转登录
- ChallengeProgressCard 新增分段进度动画，提升视觉反馈
- 升级版本号至 1.0.15

app/challenges/[id].tsx

@@ -2,6 +2,7 @@ import ChallengeProgressCard from '@/components/challenges/ChallengeProgressCard
 import { HeaderBar } from '@/components/ui/HeaderBar';
 import { Colors } from '@/constants/Colors';
 import { useAppDispatch, useAppSelector } from '@/hooks/redux';
+import { useAuthGuard } from '@/hooks/useAuthGuard';
 import { useColorScheme } from '@/hooks/useColorScheme';
 import {
   fetchChallengeDetail,
@@ -15,12 +16,12 @@ import {
   selectJoinStatus,
   selectLeaveError,
   selectLeaveStatus,
-  selectProgressError,
-  selectProgressStatus,
+  selectProgressStatus
 } from '@/store/challengesSlice';
 import { Toast } from '@/utils/toast.utils';
 import { Ionicons } from '@expo/vector-icons';
 import { BlurView } from 'expo-blur';
+import { Image } from 'expo-image';
 import { LinearGradient } from 'expo-linear-gradient';
 import { useLocalSearchParams, useRouter } from 'expo-router';
 import LottieView from 'lottie-react-native';
@@ -29,7 +30,6 @@ import {
   ActivityIndicator,
   Alert,
   Dimensions,
-  Image,
   Platform,
   ScrollView,
   Share,
@@ -82,6 +82,8 @@ export default function ChallengeDetailScreen() {
   const colorTokens = Colors[theme];
   const insets = useSafeAreaInsets();
 
+  const { ensureLoggedIn } = useAuthGuard();
+
   const challengeSelector = useMemo(() => (id ? selectChallengeById(id) : undefined), [id]);
   const challenge = useAppSelector((state) => (challengeSelector ? challengeSelector(state) : undefined));
 
@@ -103,8 +105,6 @@ export default function ChallengeDetailScreen() {
 
   const progressStatusSelector = useMemo(() => (id ? selectProgressStatus(id) : undefined), [id]);
   const progressStatus = useAppSelector((state) => (progressStatusSelector ? progressStatusSelector(state) : 'idle'));
-  const progressErrorSelector = useMemo(() => (id ? selectProgressError(id) : undefined), [id]);
-  const progressError = useAppSelector((state) => (progressErrorSelector ? progressErrorSelector(state) : undefined));
 
   useEffect(() => {
     const getData = async (id: string) => {
@@ -174,6 +174,13 @@ export default function ChallengeDetailScreen() {
     if (!id || joinStatus === 'loading') {
       return;
     }
+
+    const isLoggedIn = await ensureLoggedIn();
+    if (!isLoggedIn) {
+      // 如果未登录，用户会被重定向到登录页面
+      return;
+    }
+
     try {
       await dispatch(joinChallenge(id));
       setShowCelebration(true)
@@ -307,7 +314,7 @@ export default function ChallengeDetailScreen() {
           ]}
         >
           <View style={styles.heroContainer}>
-            <Image source={{ uri: challenge.image }} style={styles.heroImage} resizeMode="cover" />
+            <Image source={{ uri: challenge.image }} style={styles.heroImage} cachePolicy={'memory-disk'} />
             <LinearGradient
               colors={['rgba(0,0,0,0.35)', 'rgba(0,0,0,0.15)', 'rgba(244, 246, 255, 1)']}
               style={StyleSheet.absoluteFillObject}
@@ -369,6 +376,7 @@ export default function ChallengeDetailScreen() {
                         key={`${avatar}-${index}`}
                         source={{ uri: avatar }}
                         style={[styles.avatar, index > 0 && styles.avatarOffset]}
+                        cachePolicy={'memory-disk'}
                       />
                     ))}
                     {challenge.participantsCount && challenge.participantsCount > participantAvatars.length ? (
@@ -401,7 +409,7 @@ export default function ChallengeDetailScreen() {
                     <Text style={styles.rankingOrder}>{index + 1}</Text>
                   </View>
                   {item.avatar ? (
-                    <Image source={{ uri: item.avatar }} style={styles.rankingAvatar} />
+                    <Image source={{ uri: item.avatar }} style={styles.rankingAvatar} cachePolicy={'memory-disk'} />
                   ) : (
                     <View style={styles.rankingAvatarPlaceholder}>
                       <Ionicons name="person-outline" size={20} color="#6f7ba7" />