console: GitHub 风格（Primer）

保持一页式控制台排版与全部功能、API 不变，只换视觉：
深色顶栏 #24292f、Primer 浅色配色（边框 #d0d7de、链接蓝
#0969da、绿主按钮 #2da44e）、6px 圆角方框、系统字体与
等宽 ID/trace；任务列表改 issues 式（状态圆点 + 标题 +
灰色元信息）；对话改评论时间线（白框 + 头部 + 正文，
竖线连接），灰/蓝气泡已移除；自动选项目与继续消息历史
不受影响。console 标记单测本地 53 项通过。

cloud/console-react/src/components/chat/Chat.tsx

@@ -18,16 +18,19 @@ export function useAutoFollow(dep: unknown) {
   return { ref, following, onScroll };
 }
 
+// GitHub-style comment box, not a chat bubble: full-width white box
+// with a subtle header row (role label only — no timestamp or sender
+// is invented; the backend provides neither) and the body below.
+// Status entries are plain muted timeline text on the timeline line.
 export function ChatBubble({ msg }: { msg: ChatMessage }) {
   if (msg.role === "status") {
     return <div className="chat-status">{msg.text}</div>;
   }
+  const author = msg.label || (msg.role === "user" ? "用户" : msg.role === "assistant" ? "助手" : "工具");
   return (
-    <div className={"chat-row " + msg.role}>
-      <div className={"chat-bubble " + msg.role}>
-        {msg.label ? <div className="chat-label">{msg.label}</div> : null}
-        <div className="chat-text">{msg.text}</div>
-      </div>
+    <div className={"gh-comment " + msg.role}>
+      <div className="gh-comment-header"><span className="gh-comment-author">{author}</span></div>
+      <div className="gh-comment-body">{msg.text}</div>
     </div>
   );
 }
@@ -54,25 +57,24 @@ export function ChatInput({ onSend, disabled, placeholder }: {
     onSend(v);
     setText("");
   };
-  // Pill input bar, Muse screenshot style: the textarea is the pill
-  // itself, and send is a light-blue circular arrow. No mic or
-  // attachment button here: the continue chat has no voice or
-  // attachment API (attachments live in Dispatch), so a mic/+ icon
-  // would be a dead button; the left list header's + is the new-task
-  // entry instead.
+  // GitHub comment box: textarea on top, a subtle footer row with the
+  // green primary send button. No mic or attachment button here: the
+  // continue chat has no voice or attachment API (attachments live in
+  // Dispatch), so a mic/+ icon would be a dead button.
   return (
-    <div className="chat-input-bar">
+    <div className="gh-comment-box">
       <textarea
         aria-label="会话输入"
-        className="chat-input"
-        rows={1}
+        rows={3}
         placeholder={placeholder || "消息"}
         value={text}
         disabled={disabled}
         onChange={(e) => setText(e.target.value)}
         onKeyDown={(e) => { if (e.key === "Enter" && !e.shiftKey) { e.preventDefault(); send(); } }}
       />
-      <button type="button" className="chat-send" aria-label="发送" disabled={disabled || !text.trim()} onClick={send}>↑</button>
+      <div className="gh-comment-footer">
+        <button type="button" className="primary" aria-label="发送" disabled={disabled || !text.trim()} onClick={send}>发送</button>
+      </div>
     </div>
   );
 }