feat: enhance profile editing and image upload functionality

- Introduced a utility function to ensure absolute media URLs for user profile images.
- Updated the user cache synchronization method to handle profile data more effectively, including avatar, nickname, phone, and MBTI.
- Refactored the avatar upload process to utilize the new URL handling function, improving reliability.
- Modified the super article editor to focus on image uploads instead of file uploads, enhancing user experience with clearer labeling and prompts.

This update aims to streamline user profile management and improve the image upload experience in the application.

miniprogram/pages/super-article-editor/super-article-editor.wxml

@@ -8,12 +8,12 @@
   </view>
   <view style="height: {{statusBarHeight + 44}}px;"></view>
 
-  <!-- AI：参考文件 + 提示词 -->
+  <!-- AI：参考图片 + 提示词 -->
   <view class="card">
     <text class="section-title">AI 写文章</text>
-    <text class="label">参考文件（可多选）</text>
+    <text class="label">参考图片（可多选）</text>
     <view class="file-actions">
-      <view class="add-file-btn" bindtap="chooseReferenceFiles">＋ 添加文件</view>
+      <view class="add-file-btn" bindtap="chooseReferenceImages">＋ 添加图片</view>
     </view>
     <view wx:for="{{attachedFiles}}" wx:key="id" class="file-row">
       <view class="file-main">
@@ -25,7 +25,7 @@
       </view>
       <text class="file-remove" data-id="{{item.id}}" bindtap="removeAttachedFile">移除</text>
     </view>
-    <text class="hint">可选图片、TXT/MD/JSON 等文本；PDF/Office 将作为附件上传，服务端尽量抽取纯文本。单文件不超 30MB。会话文件请在真机微信内选取；开发者工具若无效可改用相册图片。</text>
+    <text class="hint">从相册或相机添加参考图，可多选（单次最多 9 张），上传后参与 AI 生成。单张建议不超 30MB。</text>
 
     <text class="label">提示词</text>
     <view class="textarea-wrap">