feat(ui): add ShareSheet component for multi-channel post sharing

Add ShareSheet component that provides native sharing options (WeChat, Moments, copy link, etc.) replacing the previous clipboard-only approach. Also change like icon from heart to thumb-up to better match the share functionality.

src/components/business/PostCard/PostCard.tsx

@@ -280,10 +280,10 @@ function createPostCardStyles(colors: AppColors) {
       marginLeft: 4,
     },
     activeActionText: {
-      color: colors.error.main,
+      color: colors.primary.main,
     },
     activeActionTextMerged: {
-      color: colors.error.main,
+      color: colors.primary.main,
       fontSize: fontSizes.sm,
       marginLeft: 4,
     },
@@ -589,7 +589,7 @@ const PostCardInner: React.FC<PostCardProps> = (normalizedProps) => {
             <Text style={styles.gridUsername} numberOfLines={1}>{author?.nickname || '匿名用户'}</Text>
           </TouchableOpacity>
           <View style={styles.gridLikeArea}>
-            <MaterialCommunityIcons name="heart-outline" size={14} color={colors.text.secondary} />
+            <MaterialCommunityIcons name="thumb-up-outline" size={14} color={colors.text.secondary} />
             <Text style={styles.gridLikeCount}>{formatNumber(post.likes_count || 0)}</Text>
           </View>
         </View>
@@ -677,9 +677,9 @@ const PostCardInner: React.FC<PostCardProps> = (normalizedProps) => {
         <View style={styles.actionButtons}>
           <TouchableOpacity style={styles.actionBtn} onPress={handleLike}>
             <MaterialCommunityIcons
-              name={post.is_liked ? 'heart' : 'heart-outline'}
+              name={post.is_liked ? 'thumb-up' : 'thumb-up-outline'}
               size={18}
-              color={post.is_liked ? colors.error.main : colors.text.secondary}
+              color={post.is_liked ? colors.primary.main : colors.text.secondary}
             />
             <Text style={post.is_liked ? styles.activeActionTextMerged : styles.actionText}>
               {post.likes_count > 0 ? formatNumber(post.likes_count) : '赞'}

src/components/business/ShareSheet/ShareSheet.tsx

@@ -0,0 +1,55 @@
+import React, { useEffect, useMemo } from 'react';
+import { Share as RNShare, Platform } from 'react-native';
+
+export interface ShareSheetProps {
+  visible: boolean;
+  postUrl?: string;
+  postTitle?: string;
+  onClose: () => void;
+  onShareAction?: (actionKey: string) => void;
+}
+
+const ShareSheet: React.FC<ShareSheetProps> = ({
+  visible,
+  postUrl,
+  postTitle,
+  onClose,
+  onShareAction,
+}) => {
+
+  const shareText = useMemo(() => {
+    const title = postTitle || '胡萝卜BBS帖子';
+    return `${title} ${postUrl || ''}`;
+  }, [postTitle, postUrl]);
+
+  useEffect(() => {
+    if (!visible) return;
+
+    const doShare = async () => {
+      try {
+        await RNShare.share(
+          {
+            message: shareText,
+            url: Platform.OS === 'ios' ? postUrl : undefined,
+            title: postTitle || '分享帖子',
+          },
+          {
+            subject: postTitle,
+            dialogTitle: '分享到',
+          }
+        );
+        onShareAction?.('system_share');
+      } catch {
+        // User cancelled
+      } finally {
+        onClose();
+      }
+    };
+
+    doShare();
+  }, [visible, shareText, postUrl, postTitle, onShareAction, onClose]);
+
+  return null;
+};
+
+export default ShareSheet;

src/components/business/ShareSheet/index.ts

@@ -0,0 +1,2 @@
+export { default } from './ShareSheet';
+export type { ShareSheetProps } from './ShareSheet';

src/components/business/index.ts

@@ -23,3 +23,4 @@ export { default as VoteCard } from './VoteCard';
 export { default as VoteEditor } from './VoteEditor';
 export { default as VotePreview } from './VotePreview';
 export { default as ReportDialog } from './ReportDialog';
+export { default as ShareSheet } from './ShareSheet';

src/screens/home/HomeScreen.tsx

@@ -29,7 +29,7 @@ import { Post } from '../../types';
 import { useUserStore, useHomeTabBarVisibilityStore, useHomeTabPressStore } from '../../stores';
 import { useCurrentUser } from '../../stores/auth';
 import { channelService, postService } from '../../services';
-import { PostCard, TabBar, SearchBar } from '../../components/business';
+import { PostCard, TabBar, SearchBar, ShareSheet } from '../../components/business';
 import type { PostCardAction } from '../../components/business/PostCard';
 import { Loading, EmptyState, Text, ImageGallery, ImageGridItem, ResponsiveGrid } from '../../components/common';
 import { useResponsive, useResponsiveSpacing } from '../../hooks/useResponsive';
@@ -203,6 +203,10 @@ export const HomeScreen: React.FC = () => {
   // 发帖弹窗状态
   const [showCreatePost, setShowCreatePost] = useState(false);
 
+  // 分享面板状态
+  const [showShareSheet, setShowShareSheet] = useState(false);
+  const [sharePost, setSharePost] = useState<Post | null>(null);
+
   useEffect(() => {
     if (showCreatePost) {
       blurActiveElement();
@@ -576,20 +580,10 @@ export const HomeScreen: React.FC = () => {
     }
   };
 
-  // 分享帖子
-  const handleShare = async (post: Post) => {
-    if (!post?.id) return;
-    try {
-      const res = await postService.sharePost(post.id, { channel: 'copy_link' });
-      if (res.ok && res.shares_count != null) {
-        postSyncService.applyShareCountUpdate(post.id, res.shares_count);
-      }
-    } catch (shareError) {
-      console.error('上报分享次数失败:', shareError);
-    }
-    const postUrl = `https://browser.littlelan.cn/post/${encodeURIComponent(post.id)}`;
-    Clipboard.setString(postUrl);
-    Alert.alert('已复制', '帖子链接已复制到剪贴板');
+  // 分享帖子 - 打开分享面板
+  const handleShare = (post: Post) => {
+    setSharePost(post);
+    setShowShareSheet(true);
   };
 
   // 删除帖子 - 删除后刷新列表
@@ -1081,6 +1075,31 @@ export const HomeScreen: React.FC = () => {
           onClose={() => setShowCreatePost(false)}
         />
       </Modal>
+
+      {/* 分享面板 */}
+      <ShareSheet
+        visible={showShareSheet}
+        postUrl={sharePost ? `https://browser.littlelan.cn/post/${encodeURIComponent(sharePost.id)}` : undefined}
+        postTitle={sharePost?.title}
+        onClose={() => {
+          setShowShareSheet(false);
+          setSharePost(null);
+        }}
+        onShareAction={(actionKey) => {
+          if (sharePost) {
+            (async () => {
+              try {
+                const res = await postService.sharePost(sharePost.id, { channel: actionKey });
+                if (res.ok && res.shares_count != null) {
+                  postSyncService.applyShareCountUpdate(sharePost.id, res.shares_count);
+                }
+              } catch (e) {
+                console.error('上报分享次数失败:', e);
+              }
+            })();
+          }
+        }}
+      />
     </SafeAreaView>
   );
 };

src/screens/home/PostDetailScreen.tsx

@@ -39,7 +39,7 @@ import { useCurrentUser } from '../../stores/auth';
 import { postService, commentService, uploadService, authService, showPrompt, voteService } from '../../services';
 import { postSyncService } from '@/services/post';
 import { useCursorPagination } from '../../hooks/useCursorPagination';
-import { CommentItem, VoteCard, ReportDialog } from '../../components/business';
+import { CommentItem, VoteCard, ReportDialog, ShareSheet } from '../../components/business';
 import { Avatar, Button, Loading, EmptyState, Text, ImageGallery, ImageGrid, ImageGridItem, AdaptiveLayout, AppBackButton } from '../../components/common';
 import { useResponsive, useResponsiveValue, useResponsiveSpacing } from '../../hooks/useResponsive';
 import { handleError } from '@/services/core';
@@ -207,6 +207,9 @@ export const PostDetailScreen: React.FC = () => {
   // 举报相关状态
   const [reportDialogVisible, setReportDialogVisible] = useState(false);
   const [reportTarget, setReportTarget] = useState<{ type: 'post' | 'comment'; id: string } | null>(null);
+
+  // 分享面板状态
+  const [shareSheetVisible, setShareSheetVisible] = useState(false);
   
   // 投票相关状态
   const [voteResult, setVoteResult] = useState<VoteResultDTO | null>(null);
@@ -515,25 +518,10 @@ export const PostDetailScreen: React.FC = () => {
     }
   }, [post]);
 
-  // 分享帖子
+  // 分享帖子 - 打开分享面板
   const handleShare = useCallback(async () => {
     if (!post?.id) return;
-    try {
-      const res = await postService.sharePost(post.id, { channel: 'copy_link' });
-      if (res.ok && res.shares_count != null) {
-        setPost((prev) =>
-          prev
-            ? { ...prev, shares_count: res.shares_count!, sharesCount: res.shares_count! }
-            : null
-        );
-        postSyncService.applyShareCountUpdate(post.id, res.shares_count);
-      }
-    } catch (error) {
-      console.error('上报分享次数失败:', error);
-    }
-    const postUrl = `https://browser.littlelan.cn/post/${encodeURIComponent(post.id)}`;
-    Clipboard.setString(postUrl);
-    Alert.alert('已复制', '帖子链接已复制到剪贴板');
+    setShareSheetVisible(true);
   }, [post?.id]);
 
   // 投票处理函数
@@ -1757,6 +1745,35 @@ export const PostDetailScreen: React.FC = () => {
           setReportTarget(null);
         }}
       />
+
+      {/* 分享面板 */}
+      <ShareSheet
+        visible={shareSheetVisible}
+        postUrl={post ? `https://browser.littlelan.cn/post/${encodeURIComponent(post.id)}` : undefined}
+        postTitle={post?.title}
+        onClose={() => {
+          setShareSheetVisible(false);
+        }}
+        onShareAction={(actionKey) => {
+          if (post) {
+            (async () => {
+              try {
+                const res = await postService.sharePost(post.id, { channel: actionKey });
+                if (res.ok && res.shares_count != null) {
+                  setPost((prev) =>
+                    prev
+                      ? { ...prev, shares_count: res.shares_count!, sharesCount: res.shares_count! }
+                      : null
+                  );
+                  postSyncService.applyShareCountUpdate(post.id, res.shares_count!);
+                }
+              } catch (error) {
+                console.error('上报分享次数失败:', error);
+              }
+            })();
+          }
+        }}
+      />
     </View>
   );
 };
@@ -1982,18 +1999,14 @@ function createPostDetailStyles(colors: AppColors) {
   commentSectionCount: {
     marginLeft: spacing.xs,
     fontSize: fontSizes.sm,
+    color: colors.text.hint,
   },
   commentSectionUnderline: {
     width: 28,
     height: 3,
     backgroundColor: colors.text.primary,
     marginTop: spacing.xs,
-    borderRadius: borderRadius.xs,
-  },
-  commentSectionCount: {
-    marginLeft: spacing.xs,
-    fontSize: fontSizes.sm,
-    color: colors.text.hint,
+    borderRadius: borderRadius.sm,
   },
   inputContainer: {
     backgroundColor: colors.background.paper,
@@ -2179,7 +2192,7 @@ function createPostDetailStyles(colors: AppColors) {
     height: 20,
     backgroundColor: colors.background.disabled,
     margin: 2,
-    borderRadius: borderRadius.xs,
+    borderRadius: borderRadius.sm,
   },
   emptyCommentsGridItemActive: {
     backgroundColor: colors.text.hint,