feat(publish): unify image fetch failure message across adapters

Consolidate per-platform cover/image fetch failure prompts into a single
PUBLISH_IMAGE_FETCH_FAILED_MESSAGE constant shared by baijiahao, bilibili,
dongchedi, qiehao, smzdm, and zol adapters, and generalize the normalizer
to match any *_image_fetch_failed / *_cover_fetch_failed code. Also split
desktop publish list loading into initial vs manual-refresh states so the
refresh button no longer blanks the table, and fix admin-web active-task
detection to cover all pending statuses.

apps/desktop-client/src/main/adapters/zol.ts

@@ -1,5 +1,6 @@
 import type { JsonValue } from '@geo/shared-types'
 
+import { PUBLISH_IMAGE_FETCH_FAILED_MESSAGE } from '../../shared/publisher-errors'
 import type { PublishAdapter, PublishAdapterContext } from './base'
 import {
   extractImageSources,
@@ -488,7 +489,7 @@ function failureResult(
   if (message.startsWith('zol_cover_fetch_failed')) {
     return {
       status: 'failed',
-      summary: '中关村在线封面文件读取失败，请重新上传封面图后重试。',
+      summary: PUBLISH_IMAGE_FETCH_FAILED_MESSAGE,
       error: {
         code: 'zol_cover_fetch_failed',
         message,