修复桌面端会话内错误提示完全不可见、收藏发送面板显示空白/裸类型名、delivery-marker图标className拼出undefined

- 桌面布局下打开一个会话时，sidepanel-view.jsx 走的是 messages-home 分支（渲染
  MessageCenterView），这个分支从来没有渲染过ErrorPanel；messages-view.jsx自己的ErrorPanel
  又只在displayMobile时才渲染——两边一凑，桌面端（最常见的使用状态）里任何onError(...)调用
  （上传失败、收藏转发失败、URL风控拦截等）全部没有可见的展示出口，用户只会觉得"点了但什么
  反应都没有"。已用真实handleError()调用实测确认：修复前DOM里根本没有.info-box节点，修复后
  正确渲染且visible。
- "我的收藏"发送面板：favoriteSummary()对图片/视频收藏显示空白（真实数据里这两类的
  snapshot.content.txt是占位用的单个空格，被直接当文本展示）、对文本类收藏显示裸露的内部
  类型字符串"text"（FAVORITE_TYPE_LABEL没有text这个key，且文本收藏的content本身就是纯字符串
  而非{txt:...}对象，原逻辑没处理这种形状）。改成图片/视频/语音三类固定用类型标签、文本类型
  优先判断content本身是不是纯字符串、并给FAVORITE_TYPE_LABEL补上text条目。
- received-marker.jsx的已发送/已送达图标（deliveryMarker对这两种状态返回的对象没有color字段）
  拼接className时把undefined直接字符串化拼了进去，实际渲染成"material-icons small undefined"。

均已重新构建验证；received-marker/favoriteSummary为纯函数级修复，逻辑经过仔细核对但未逐一
截图复核（不依赖运行时状态，风险低）。

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/views/sidepanel-view.jsx

@@ -164,6 +164,17 @@ class SidepanelView extends React.PureComponent {
           myUserId={this.props.myUserId}
           onTopicSelected={this.props.onTopicSelected}
           onOpenScanner={this.props.onOpenScanner} />
+        {/* This branch never rendered ErrorPanel at all -- on desktop (non-mobile), opening a real
+            conversation lands here (view stays 'messages-home' behind the split-view topic pane),
+            and messages-view.jsx's own ErrorPanel is only rendered on displayMobile. Every
+            this.props.onError(...) call reachable from an open conversation on desktop (failed
+            uploads, failed forwards, URL risk blocks, etc.) had no visible outlet at all. */}
+        <ErrorPanel
+          level={this.props.errorLevel}
+          text={this.props.errorText}
+          action={this.props.errorAction}
+          actionText={this.props.errorActionText}
+          onClearError={this.props.onError} />
       </div>;
     }
 

src/widgets/received-marker.jsx

@@ -38,7 +38,10 @@ class ReceivedMarker extends React.PureComponent {
     }
 
     const icon = deliveryMarker(this.props.received);
-    const marker = icon ? <i className={'material-icons small ' + icon.color}>{icon.name}</i> : null;
+    // icon.color is only set for the failed/read cases (deliveryMarker's other {name} results omit
+    // the key entirely) -- string-concatenating it unconditionally put the literal text "undefined"
+    // into the className for sending/sent/received messages.
+    const marker = icon ? <i className={'material-icons small ' + (icon.color || '')}>{icon.name}</i> : null;
     const edited = this.props.edited ? formatMessage(messages.message_edited_marker) : null;
 
     return (

src/widgets/send-message.jsx

@@ -30,12 +30,20 @@ const EMOJI_LIST = ['😀', '😁', '😂', '🤣', '😃', '😄', '😅', '
 // 互相 import，就近各自维护一份小常量）。收藏摘要要优先读 snapshot.content.txt 这个结构化字段，
 // 不能像最初那版一样直接展示 snapshot.text——那是整条 content 原样 JSON.stringify 的结果
 // （例如 {"txt":"..."}），不是给人看的，之前联调时真被这个坑绊了一次才发现。
-const FAVORITE_TYPE_LABEL = {image: '[图片]', video: '[视频]', voice: '[语音]', file: '[文件]', link: '[链接]'};
+const FAVORITE_TYPE_LABEL = {image: '[图片]', video: '[视频]', voice: '[语音]', file: '[文件]', link: '[链接]', text: '[文本]'};
 function favoriteSummary(item) {
-  const content = item.snapshot && item.snapshot.content;
-  if (content && typeof content.txt === 'string' && content.txt) {
-    return content.txt;
+  // image/video/voice favorites' snapshot.content.txt is a placeholder single space in this
+  // project's convention (confirmed via a real GET /favorites response) -- reading it as the
+  // summary showed a blank line instead of a type label for these three types.
+  if (item.type === 'image' || item.type === 'video' || item.type === 'voice') {
+    return FAVORITE_TYPE_LABEL[item.type];
   }
+  const content = item.snapshot && item.snapshot.content;
+  // A text favorite's snapshot.content is a plain string, not a {txt:...} Drafty object --
+  // content.txt on it is undefined, which used to fall through all the way to the internal
+  // item.type value ("text") being shown to the user verbatim.
+  if (typeof content === 'string' && content.trim()) return content;
+  if (content && typeof content.txt === 'string' && content.txt.trim()) return content.txt;
   return FAVORITE_TYPE_LABEL[item.type] || item.type || item.favorite_id;
 }
 const RECENT_EMOJI_KEY = 'im-recent-emoji';