feat(asset): 成长规划师任务模板封面接入素材库 + 补 getEditorCustomAlert 具名导出

- GuidePackages.vue：老 action="/api/upload"（后端已无此路由）改为 /api/admin/file-record/upload（category=guide-packages + Bearer），新增「从素材库选择」与 AssetPicker
- editorAssetUpload.js：getEditorCustomAlert 改为具名导出，修复 3 个 wangEditor 页面 import 告警

cfc-web/src/utils/editorAssetUpload.js

@@ -13,7 +13,7 @@ import { resolveAssetUrl } from './asset'
 
 const BASE_URL = process.env.VUE_APP_BASE_API || ''
 
-function getUploadHeaders() {
+export function getUploadHeaders() {
   const token = localStorage.getItem('token')
   return token ? { Authorization: 'Bearer ' + token } : {}
 }
@@ -32,7 +32,19 @@ function makeCustomInsert() {
   }
 }
 
-function makeCustomAlert() {
+/**
+ * 编辑器顶层 config.customAlert 工厂。
+ *
+ * <p>注意：wangEditor 从编辑器顶层 config.customAlert 读取（不是 MENU_CONF.uploadImage.customAlert），
+ * 因此必须挂在 editorConfig 根节点上：
+ * <pre>
+ * editorConfig = {
+ *   customAlert: getEditorCustomAlert(),
+ *   MENU_CONF: buildEditorAssetMenuConf({ category: 'articles' })
+ * }
+ * </pre>
+ */
+export function getEditorCustomAlert() {
   // 注意：wangEditor 从编辑器顶层 config.customAlert 读取（不是 MENU_CONF.uploadImage.customAlert）
   return function customAlert(msg, type) {
     Message({ message: msg, type: type || 'error' })
@@ -132,6 +144,6 @@ export function insertAssetIntoEditor(editor, record, type) {
 export default {
   buildEditorAssetMenuConf,
   insertAssetIntoEditor,
-  getEditorCustomAlert: makeCustomAlert,
+  getEditorCustomAlert,
   getUploadHeaders
 }