refactor(PostCard, PostCard.legacy): remove legacy PostCard component and update exports

- Deleted the legacy PostCard component to streamline the codebase and improve maintainability.
- Updated exports in PostCard and index files to remove references to the legacy component.
- Adjusted PostCardProps to eliminate legacy properties, ensuring only the new API is supported.
- Enhanced the PostCard component to focus on modern implementation and features.

src/screens/home/HomeScreen.tsx

@@ -512,14 +512,7 @@ export const HomeScreen: React.FC = () => {
             <PostCard
               post={post}
               variant="grid"
-              onPress={() => handlePostPress(post.id)}
-              onUserPress={() => authorId && handleUserPress(authorId)}
-              onLike={() => handleLike(post)}
-              onComment={() => handlePostPress(post.id, true)}
-              onBookmark={() => handleBookmark(post)}
-              onShare={() => handleShare(post)}
-              onImagePress={(images, index) => handleImagePress(images, index)}
-              onDelete={() => handleDeletePost(post.id)}
+              onAction={(action) => handlePostAction(post, action)}
               isPostAuthor={isPostAuthor}
             />
           </View>
@@ -579,15 +572,8 @@ export const HomeScreen: React.FC = () => {
             <PostCard
               key={post.id}
               post={post}
-              variant={viewMode === 'grid' ? 'grid' : 'default'}
-              onPress={() => handlePostPress(post.id)}
-              onUserPress={() => authorId && handleUserPress(authorId)}
-              onLike={() => handleLike(post)}
-              onComment={() => handlePostPress(post.id, true)}
-              onBookmark={() => handleBookmark(post)}
-              onShare={() => handleShare(post)}
-              onImagePress={(images, index) => handleImagePress(images, index)}
-              onDelete={() => handleDeletePost(post.id)}
+              variant={viewMode === 'grid' ? 'grid' : 'list'}
+              onAction={(action) => handlePostAction(post, action)}
               isPostAuthor={isPostAuthor}
             />
           );

src/screens/home/PostDetailScreen.tsx

@@ -281,8 +281,25 @@ export const PostDetailScreen: React.FC = () => {
     if (!post?.author) return;
     
     const author = post.author;
+    const handleBackPress = () => {
+      if (navigation.canGoBack()) {
+        navigation.goBack();
+        return;
+      }
+      navigation.navigate('Main', {
+        screen: 'HomeTab',
+        params: { screen: 'Home', params: undefined },
+      });
+    };
     
     navigation.setOptions({
+      headerBackVisible: false,
+      headerTitleAlign: 'left',
+      headerLeft: () => (
+        <TouchableOpacity onPress={handleBackPress} style={styles.headerBackButton} hitSlop={8}>
+          <MaterialCommunityIcons name="arrow-left" size={24} color={colors.text.primary} />
+        </TouchableOpacity>
+      ),
       headerTitle: () => (
         <View style={styles.headerContainer}>
           <TouchableOpacity
@@ -298,7 +315,9 @@ export const PostDetailScreen: React.FC = () => {
           <View style={styles.headerUserInfo}>
             <TouchableOpacity onPress={() => handleUserPress(author.id)}>
               <Text style={styles.headerNickname} numberOfLines={1}>
-                {author.nickname}
+                {author.nickname && author.nickname.length > 10
+                  ? `${author.nickname.slice(0, 10)}...`
+                  : author.nickname}
               </Text>
             </TouchableOpacity>
           </View>
@@ -1701,7 +1720,7 @@ const styles = StyleSheet.create({
     flexDirection: 'row',
     alignItems: 'center',
     flex: 1,
-    marginLeft: -8,
+    marginLeft: spacing.sm,
   },
   headerAvatarWrapper: {
     marginRight: spacing.sm,
@@ -1720,6 +1739,12 @@ const styles = StyleSheet.create({
     alignItems: 'center',
     marginRight: spacing.sm,
   },
+  headerBackButton: {
+    paddingHorizontal: spacing.xs,
+    paddingVertical: spacing.xs,
+    marginLeft: spacing.xs,
+    marginRight: spacing.sm,
+  },
   // 帖子容器
   postContainer: {
     backgroundColor: colors.background.paper,

src/screens/home/SearchScreen.tsx

@@ -22,6 +22,7 @@ import { Post, User } from '../../types';
 import { useUserStore } from '../../stores';
 import { postService, authService } from '../../services';
 import { PostCard, TabBar, SearchBar } from '../../components/business';
+import type { PostCardAction } from '../../components/business/PostCard';
 import { Avatar, EmptyState, Text, ResponsiveGrid, Loading } from '../../components/common';
 import { HomeStackParamList } from '../../navigation/types';
 import { useResponsive, useResponsiveSpacing, useResponsiveValue } from '../../hooks/useResponsive';
@@ -175,6 +176,41 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack, navigation:
     navigation.navigate('UserProfile', { userId });
   };
 
+  // 统一处理 PostCard 的操作（搜索页不支持删除）
+  const handlePostAction = (post: Post, action: PostCardAction) => {
+    switch (action.type) {
+      case 'press':
+        handlePostPress(post.id);
+        break;
+      case 'userPress':
+        if (post.author?.id) {
+          handleUserPress(post.author.id);
+        }
+        break;
+      case 'like':
+        postService.likePost(post.id);
+        break;
+      case 'unlike':
+        postService.unlikePost(post.id);
+        break;
+      case 'comment':
+        handlePostPress(post.id, true);
+        break;
+      case 'bookmark':
+        postService.favoritePost(post.id);
+        break;
+      case 'unbookmark':
+        postService.unfavoritePost(post.id);
+        break;
+      case 'share':
+        // 搜索页暂不处理分享
+        break;
+      case 'imagePress':
+      case 'delete':
+        break;
+    }
+  };
+
   // 获取当前搜索类型
   const getSearchType = (): SearchType => {
     switch (activeIndex) {
@@ -222,13 +258,9 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack, navigation:
               <PostCard
                 key={post.id}
                 post={post}
-                onPress={() => handlePostPress(post.id)}
-                onUserPress={() => post.author ? handleUserPress(post.author.id) : () => {}}
-                onLike={() => {}}
-                onComment={() => handlePostPress(post.id, true)}
-                onBookmark={() => {}}
-                onShare={() => {}}
-                compact={isMobile}
+                onAction={(action) => handlePostAction(post, action)}
+                variant="list"
+                features={isMobile ? 'compact' : 'full'}
               />
             ))}
           </ResponsiveGrid>
@@ -248,13 +280,9 @@ export const SearchScreen: React.FC<SearchScreenProps> = ({ onBack, navigation:
         renderItem={({ item }) => (
           <PostCard
             post={item}
-            onPress={() => handlePostPress(item.id)}
-            onUserPress={() => item.author ? handleUserPress(item.author.id) : () => {}}
-            onLike={() => {}}
-            onComment={() => handlePostPress(item.id, true)}
-            onBookmark={() => {}}
-            onShare={() => {}}
-            compact
+            onAction={(action) => handlePostAction(item, action)}
+            variant="list"
+            features="compact"
           />
         )}
         keyExtractor={item => item.id}