refactor: standardize pagination response structure and enhance cursor handling

- Update various services and hooks to replace 'items' with 'list' for consistency in pagination responses.
- Modify PostRepository, commentService, groupService, messageService, and postService to align with the new response structure.
- Enhance cursor pagination logic in hooks and components to ensure proper handling of pagination states.
- Refactor HomeScreen, PostDetailScreen, SearchScreen, and other components to utilize the updated pagination structure.

src/services/groupService.ts

@@ -341,7 +341,7 @@ class GroupService {
     } catch (error) {
       console.error('获取群组列表失败:', error);
       return {
-        items: [],
+        list: [],
         next_cursor: null,
         prev_cursor: null,
         has_more: false,
@@ -368,7 +368,7 @@ class GroupService {
     } catch (error) {
       console.error('获取群组成员列表失败:', error);
       return {
-        items: [],
+        list: [],
         next_cursor: null,
         prev_cursor: null,
         has_more: false,
@@ -395,7 +395,7 @@ class GroupService {
     } catch (error) {
       console.error('获取群公告列表失败:', error);
       return {
-        items: [],
+        list: [],
         next_cursor: null,
         prev_cursor: null,
         has_more: false,