refactor(post): consolidate post sync to PostSyncService and remove ProcessPostUseCase

- Replace ProcessPostUseCase with new PostSyncService in src/services/post/
- Add postListStore for state management in src/stores/post/
- Remove deprecated ProcessPostUseCase and ProcessMessageUseCase files
- Delete architecture documentation files (ARCHITECTURE_REFACTOR_PLAN.md, architecture-comparison-report.md)
- Update all consumers (HomeScreen, PostDetailScreen, SearchScreen, useUserProfile, useDifferentialPosts)
- Simplify postService to only contain API layer methods
- Remove unused type exports from message stores

BREAKING CHANGE: ProcessPostUseCase and ProcessMessageUseCase have been removed.
Use postSyncService for post operations instead.

src/screens/home/PostDetailScreen.tsx

@@ -37,7 +37,7 @@ import { Post, Comment, VoteResultDTO, VoteOptionDTO } from '../../types';
 import { useUserStore } from '../../stores';
 import { useCurrentUser } from '../../stores/authStore';
 import { postService, commentService, uploadService, authService, showPrompt, voteService } from '../../services';
-import { processPostUseCase } from '../../core/usecases/ProcessPostUseCase';
+import { postSyncService } from '../../services/post/PostSyncService';
 import { useCursorPagination } from '../../hooks/useCursorPagination';
 import { CommentItem, VoteCard, ReportDialog } from '../../components/business';
 import { Avatar, Button, Loading, EmptyState, Text, ImageGallery, ImageGrid, ImageGridItem, AdaptiveLayout, AppBackButton } from '../../components/common';
@@ -238,7 +238,7 @@ export const PostDetailScreen: React.FC = () => {
 
     try {
       // 使用 ProcessPostUseCase 获取帖子详情
-      const postData = await processPostUseCase.fetchPostById(postId);
+      const postData = await postSyncService.fetchPostById(postId);
       if (postData) {
         // 类型转换：将 core/entities/Post 转换为 PostDTO 以保持兼容性
         setPost(postData as unknown as Post);
@@ -487,9 +487,9 @@ export const PostDetailScreen: React.FC = () => {
     
     try {
       if (originalPost.is_liked) {
-        await processPostUseCase.unlikePost(post.id);
+        await postSyncService.unlikePost(post.id);
       } else {
-        await processPostUseCase.likePost(post.id);
+        await postSyncService.likePost(post.id);
       }
     } catch (error) {
       handleError(error, { context: '点赞' });
@@ -505,9 +505,9 @@ export const PostDetailScreen: React.FC = () => {
     
     try {
       if (originalPost.is_favorited) {
-        await processPostUseCase.unfavoritePost(post.id);
+        await postSyncService.unfavoritePost(post.id);
       } else {
-        await processPostUseCase.favoritePost(post.id);
+        await postSyncService.favoritePost(post.id);
       }
     } catch (error) {
       handleError(error, { context: '收藏' });
@@ -526,7 +526,7 @@ export const PostDetailScreen: React.FC = () => {
             ? { ...prev, shares_count: res.shares_count!, sharesCount: res.shares_count! }
             : null
         );
-        processPostUseCase.applyShareCountUpdate(post.id, res.shares_count);
+        postSyncService.applyShareCountUpdate(post.id, res.shares_count);
       }
     } catch (error) {
       console.error('上报分享次数失败:', error);
@@ -635,7 +635,7 @@ export const PostDetailScreen: React.FC = () => {
           onPress: async () => {
             setIsDeleting(true);
             try {
-              await processPostUseCase.deletePost(post.id);
+              await postSyncService.deletePost(post.id);
               Alert.alert('删除成功', '帖子已删除', [
                 {
                   text: '确定',