🐛 修复分享链接打开方式

- 添加openShare方法替代直接调用window.open
- 处理弹窗被浏览器阻止的情况，自动退回当前页跳转

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/app.html

@@ -2116,7 +2116,7 @@
               <span><i class="fas fa-calendar-alt"></i> 创建 {{ formatDateTime(share.created_at) }}</span>
             </div>
             <div class="share-card__actions">
-              <button class="btn btn-secondary" @click.stop="window.open(share.share_url, '_blank')">
+              <button class="btn btn-secondary" @click.stop="openShare(share.share_url)">
                 <i class="fas fa-external-link-alt"></i> 打开
               </button>
               <button class="btn btn-secondary" @click.stop="copyShareLink(share.share_url)">