fix(chat): use teacher conversation placeholder

.project-docs/30-worklog/tasks/20260928-teacher-hover-intro-a73f6e29.md

@@ -40,6 +40,10 @@
 - Same-task ownership resumed and verified; previously loaded project context still applies. Refreshed the active peer agent-refresh record: it now implements catalog refresh on top of 862477f in its own checkout and explicitly leaves the running trial alone. Code-path overlap is limited to separate concerns in TeacherChatPanel; no semantic conflict. Gate passed.
 - Remove the two elements, run existing focused verification and compile, then apply equivalent targeted hiding to the running trial without reloading its in-memory drafts or changing focus.
 
+## Follow-up Plan: Composer Placeholder
+
+- User requests the exact placeholder “和老师聊聊”. Same-task start/status identity matches; earlier loaded context remains applicable, peer refresh work is isolated and semantically separate. Gate passed. Change only the placeholder, compile, and update the live trial attribute without replacing input values or moving focus.
+
 ## Outcome
 
 - Added a cream, rounded introduction card using the published teacher name, avatar and description. Hover or keyboard focus opens one card at a time outside the scrolling topbar; empty descriptions do not create a card. The pointer can enter the card to read long descriptions. Leaving, Escape or clicking the entry closes it; moving inside the clicked entry does not reopen it until a fresh entry.
@@ -68,6 +72,8 @@
 
 - Footer-copy follow-up: removed the redundant invitation to type below and omitted-history message count from TeacherChatPanel; context metadata and other response behavior are unchanged. Existing coding-teacher-ui tests (38) passed, as did typecheck, scoped ESLint and production build. The live trial had three matching footer paragraphs; all three became invisible after the targeted presentation update. PID 27713, current input values and foreground PID were preserved; no reload, message or window activation occurred. Temporary inspector was closed afterward.
 
+- Placeholder follow-up: changed the source textarea placeholder to exactly “和老师聊聊”. Typecheck, scoped ESLint and production compilation passed. Updated the same live Renderer attribute and installed a scoped observer for subsequent panel remounts until its next normal load. Verified the exact placeholder, unchanged input values/focus, unchanged foreground app and same PID 27713. No restart/reload or message occurred; temporary inspector closed after the update.
+
 ## Follow-ups
 
 - Integrate this branch when requested; retain this worktree because the updated trial now runs its compiled output. The user can activate the existing `Makelore Teacher Trial` Dock entry to review the interface.

README.md

@@ -168,7 +168,7 @@ Pi 正式包必须继续运行 `pnpm run verify:artifact:pi`、`pnpm run smoke:p
 
 - Code 课堂左侧项目栏默认宽 171px，可拖动右边缘在 128–256px 间调整，双击恢复默认并在本机记住宽度；标题栏同步对齐。项目名与会话名超长省略并可悬停查看；右侧咨询栏默认宽 508px，可拖动至 640px，紧凑窗口仍使用覆盖式咨询。
 - 客户端没有内置老师／朋友角色。已下发智能体以头像和名称并排显示在标题栏，点击后打开对应智能体的讨论；数量较多时横向滚动，咨询面板不再提供智能体下拉框。名称、头像、简介、欢迎语和推荐问题均由服务端提供。首次使用默认选择运营指定项，各智能体的未发送草稿分别保存，已有话题保持绑定的版本；旧的未分配项目草稿可展开查看，不自动转给其他智能体。打开或切换只读取配置和历史，不触发模型；咨询栏支持调整宽度和重新打开。
-- 鼠标悬停或键盘聚焦顶部智能体入口时，以奶油色圆角卡片显示该智能体的发布介绍；离开、Escape 或点击入口后收起，没有介绍则不显示空卡片。咨询栏不再显示重复的头像、名称标题条，也不显示介绍及新话题、展开、关闭三个图标；老师身份保留在顶部入口及消息署名中。智能体生成的追加问题以淡蓝、奶油黄、淡紫卡片依次承载，正文 16px、行高 1.8，保留整卡点击发送与忙碌时禁用。回复下方不再显示重复的输入引导或省略早期消息条数。再次点击当前入口或在咨询栏按 Escape 可收起，切换其他入口仍直接打开对应讨论；拖动边缘调宽保留，新话题文字入口收在展开的“以往讨论”中。悬浮介绍不会创建话题、调用模型或确认未读消息，作品原生预览同时避让介绍卡和真实主动气泡。
+- 鼠标悬停或键盘聚焦顶部智能体入口时，以奶油色圆角卡片显示该智能体的发布介绍；离开、Escape 或点击入口后收起，没有介绍则不显示空卡片。咨询栏不再显示重复的头像、名称标题条，也不显示介绍及新话题、展开、关闭三个图标；老师身份保留在顶部入口及消息署名中。智能体生成的追加问题以淡蓝、奶油黄、淡紫卡片依次承载，正文 16px、行高 1.8，保留整卡点击发送与忙碌时禁用。回复下方不再显示重复的输入引导或省略早期消息条数；输入框提示为“和老师聊聊”。再次点击当前入口或在咨询栏按 Escape 可收起，切换其他入口仍直接打开对应讨论；拖动边缘调宽保留，新话题文字入口收在展开的“以往讨论”中。悬浮介绍不会创建话题、调用模型或确认未读消息，作品原生预览同时避让介绍卡和真实主动气泡。
 - 主动发言采用紧贴小头像的短气泡；只有存在真实主动消息或运营欢迎语时才显示这组浮层，收起消息时头像和气泡一起消失，顶部入口仍保留。长消息在气泡中最多显示三行，点击接回原智能体对话查看全文。不提供“智能体偶尔来看看”开关或本地模拟巡看控制，既有自动跟进与真实消息接收逻辑保留。作品原生预览对整组气泡和头像测量避让，避免图片被原生页面遮住。
 - 学生在当前项目创作时，前端每 5 分钟请求一次智能体跟进；窗口隐藏、来源归档、主对话正在执行、智能体正在回复或学生正在智能体栏写草稿时延后。Main 再检查在线启停、来源归属、项目级冷却和已完成文本指纹，未变上下文按下述十五分钟冷却处理。跟进沿用运营模型、已发布 Skills 与当前智能体话题，生成简短的具体建议或引导；以主动智能体发言持久化，不伪造学生消息。模型调用沿用智能体计费规则。
 - 进入项目时，智能体头像旁先显示运营发布的欢迎语气泡，不调用模型、不声称已检查项目；每个账号／项目主动收起后不重复弹出。真实的未读主动建议优先替换欢迎语。主动发言在头像旁直接显示气泡，不抢焦点、不盖住作品；作品区按气泡与原生预览的实际交叠范围避让，已有工具栏高度计入计算，气泡位于独立智能体栏时不额外留白，窗口／分栏尺寸变化和收起气泡时实时归还空间；“和智能体聊聊”接回同一段咨询，“等会儿聊”收起并保留历史。已有未处理气泡时不堆叠新邀请；咨询已展开时也显示气泡，直到学生主动点击查看或收起，期间的其他回复不会吞掉未读邀请。五分钟检查计时在刷新和项目切换后保留；智能体咨询里的新讨论也算进展，即使操作对话没有变化也会继续跟进；上下文完全未变时放缓到十五分钟一次，不永久停止。事件连接丢失时，每十五秒只读同步未完成回复，收到结果后停止轮询，不重复调用模型。失败如实提示，不以本地文案替代模型回复。已接受请求恢复使用原身份，退出账号和来源删除仍沿用 Main 中止边界。

src/pages/Chat/TeacherChatPanel.tsx

@@ -464,7 +464,7 @@ export function TeacherChatPanel({
         {references.length > 0 && <div className="mb-2 rounded-lg bg-white p-3 text-xs"><p className="line-clamp-3 whitespace-pre-wrap">{references.map((ref) => ref.text).join('\n')}</p><button type="button" className="mt-1 underline" onClick={removeReferences}>移除引用</button></div>}
         <div className="consultation-composer rounded-2xl border bg-white p-3 focus-within:ring-2 focus-within:ring-black/5">
           {activeFocus && <DiscussionFocus label={activeFocus.label} onClear={() => setFocus(null)} />}
-          <textarea ref={inputRef} aria-label={`向${label}提问`} value={text} disabled={busy} maxLength={6000} onChange={(e) => changeText(e.target.value)} placeholder={`想和${label}聊些什么？`} rows={2}
+          <textarea ref={inputRef} aria-label={`向${label}提问`} value={text} disabled={busy} maxLength={6000} onChange={(e) => changeText(e.target.value)} placeholder="和老师聊聊" rows={2}
             onKeyDown={(e) => { if (e.key === 'Enter' && !e.shiftKey && !e.nativeEvent.isComposing) { e.preventDefault(); void send(); } }}
             className="min-h-[60px] w-full resize-none border-0 bg-transparent text-[13px] leading-6 outline-none placeholder:text-muted-foreground/65" />
           <div className="mt-2 flex items-center justify-between gap-2" data-testid="consultation-composer-actions">