refactor(posts): use PostImage type for images in PostDetail

src/api/posts.ts

@@ -1,5 +1,5 @@
 import apiClient from './client'
-import type { Post, ApiResponse, PaginatedResponse } from '@/types'
+import type { Post, PostImage, ApiResponse, PaginatedResponse } from '@/types'
 
 // 帖子查询参数
 export interface PostQueryParams {
@@ -16,7 +16,7 @@ export interface PostQueryParams {
 export interface PostDetail extends Post {
   group_id?: string
   group_name?: string
-  images?: string[]
+  images?: PostImage[]
   tags?: string[]
   is_pinned: boolean
   is_featured: boolean