diff --git a/.env.example b/.env.example
index be2f9ef..9b5fd8c 100644
--- a/.env.example
+++ b/.env.example
@@ -27,6 +27,12 @@ LAZYBOY_COMPUTER_DRIVER=cua
 # Linux only (optional): point this at the host's LXCFS root to make htop/free
 # report the per-Agent cgroup quota. Leave the default empty directory on macOS.
 LAZYBOY_LXCFS_ROOT=./data/lxcfs
+# 群組聊天「誰該回應」：沒被 @ 的時候，由一次短短的模型問從成員的工作內容與簡介裡
+# 挑出最多三個人回覆。留空（預設）＝沿用空間的預設模型，多數人不用理這行；
+# 想省 token 就填一個便宜快速的 model id（要跟空間預設來自同一家 provider）。
+# 挑不到人、模型不能用、或超過 1.2 秒，一律由主持人（群組第一位成員）收場。
+LAZYBOY_ROUTER_MODEL=
+
 # 任務長度政策：不再用固定輪數掐掉任務。正常任務一路做到驗證完成，只有
 # 真的鬼打牆（同一個動作重複、同一個錯誤一直失敗、很久沒有新的成功）才會被
 # 提示、接著暫停等你決定；最後兩個是防迴圈失控烧 token 的保險絲，不是額度。
diff --git a/README.md b/README.md
index 45e189a..77ebf26 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ This is an early `0.1.0` release with desktop and phone browser UIs. You bring y
 - **A lasting workspace**: each agent has its own chats, run history, and optional long-term memory.
 - **A real computer**: open pages, use the terminal, organize files, drive the GUI — and watch it live.
 - **Take over any time**: sign in, pass a check, or nudge things by hand on the same desktop, then hand it back.
-- **Several agents and groups**: shared Team computers or private dedicated desktops.
+- **Several agents and groups**: shared Team computers or private dedicated desktops; `@name` decides who answers, so a message wakes the one agent it is for instead of all of them.
 - **Teach by demo, then schedule**: turn a walkthrough into a skill; use cron for repeat work.
 - **Your models and tools**: xAI, OpenCode Go, OpenAI-compatible endpoints, MCP, and file skills.
 - **Voice calls**: after you enable a voice provider, you can talk to the agent on a call.
diff --git a/README.zh-TW.md b/README.zh-TW.md
index b79e244..7a2aa7d 100644
--- a/README.zh-TW.md
+++ b/README.zh-TW.md
@@ -25,7 +25,7 @@ LazyBoy 讓 Agent 在 Docker 裡使用自己的 Linux 桌面，操作瀏覽器
 - **持續的工作空間**：每個 Agent 有自己的對話、工作紀錄與可設定的長期記憶。
 - **真的能操作電腦**：開網頁、使用終端、整理檔案、操作圖形介面，過程可即時觀看。
 - **隨時人工接管**：在同一個桌面完成登入、驗證或手動調整，再交回 Agent。
-- **多 Agent 與群組**：支援 Team 共用電腦與 Private 獨立電腦模式。
+- **多 Agent 與群組**：支援 Team 共用電腦與 Private 獨立電腦模式；群組裡 @誰就由誰回，沒點名時只叫醒工作內容相關的那個，不會全部出動。
 - **示範教學與排程**：把操作示範整理成技能，使用 cron 安排重複工作。
 - **自選模型與工具**：支援 xAI、OpenCode Go、OpenAI 相容端點，以及 MCP 與檔案技能。
 - **語音通話**：設定語音服務後，可以透過通話與 Agent 互動。
diff --git a/apps/web/src/App.tsx b/apps/web/src/App.tsx
index fadaa74..bdba7f1 100644
--- a/apps/web/src/App.tsx
+++ b/apps/web/src/App.tsx
@@ -1,4 +1,4 @@
-import { FormEvent, KeyboardEvent as ReactKeyboardEvent, useCallback, useEffect, useMemo, useRef, useState } from "react";
+import { FormEvent, Fragment, KeyboardEvent as ReactKeyboardEvent, useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { BotIcon, Brain, ChevronDown, ChevronsRight, CircleHelp, ClipboardPaste, Computer, Download, Ellipsis, Info, LogOut, Megaphone, Paperclip, Pencil, Pin, Plug, Plus, RefreshCw, Settings, Smartphone, Sparkle, Square, Upload, Users, X } from "./animated-icons";
 import UseAnimations from "./use-animations";
 import loading from "react-useanimations/lib/loading";
@@ -17,6 +17,8 @@ import searchToX from "react-useanimations/lib/searchToX";
 import { api, ApiError } from "./api";
 import { createCoalescer, subscribeToSession } from "./live";
 import { applyReplyEvent, type ReplyDrafts } from "./reply-stream";
+import { acceptMention, mentionChoices, mentionToken } from "./mentions";
+import { clockTime, dayLabel, sameDay } from "./chat-time";
 import { HANDOFF_MS, VEIL_FADE_MS, handoffRemaining, keepScreenUrl, nextVeil, viewOnlyFor, viewerPath, type Veil } from "./handoff";
 import { Avatar, AvatarLookProvider, AvatarStack, BLOBATAR_BACKGROUNDS, BLOBATAR_EXPRESSIONS, BLOBATAR_SHAPES, DEFAULT_LOOK, persistBlobatarShape, readAvatarLooks, resolveBlobatarShape, writeAvatarLook, type AvatarBackground, type AvatarExpression, type AvatarLook } from "./avatar";
 import { dateLocale, getLocale, listJoin, setLocale, t, useLocale, type MessageKey } from "./i18n";
@@ -55,10 +57,17 @@ type WorkspacePrefs={name:string;showHidden:boolean};
 function isDefaultWorkspaceName(name?:string|null){return !name||name==="Local workspace"||name==="本機工作區"}
 function readWorkspace():WorkspacePrefs{try{const raw=localStorage.getItem(WORKSPACE_STORE);if(!raw)return{name:t("localWorkspace"),showHidden:false};const value=JSON.parse(raw) as {name?:string;showHidden?:boolean};const name=value.name?.trim();return{name:isDefaultWorkspaceName(name)?t("localWorkspace"):name||t("localWorkspace"),showHidden:Boolean(value.showHidden)}}catch{return{name:t("localWorkspace"),showHidden:false}}}
 
+// A message shows only its clock time; the day it belongs to is written once,
+// in the divider above the first message of that day, the way chat apps do.
 function MessageTime({value}:{value:string}){
   const date=new Date(value);
   if(!Number.isFinite(date.getTime()))return null;
-  return <time className="message-time" dateTime={date.toISOString()} title={date.toLocaleString(dateLocale())}>{date.toLocaleString(dateLocale(),{month:"2-digit",day:"2-digit",hour:"2-digit",minute:"2-digit",second:"2-digit",hour12:false})}</time>;
+  return <time className="message-time" dateTime={date.toISOString()} title={date.toLocaleString(dateLocale())}>{clockTime(date,dateLocale())}</time>;
+}
+function DayDivider({value}:{value:string}){
+  const date=new Date(value);
+  if(!Number.isFinite(date.getTime()))return null;
+  return <div className="day-divider" role="separator" aria-label={date.toLocaleDateString(dateLocale())}><time dateTime={date.toISOString()} title={date.toLocaleDateString(dateLocale(),{dateStyle:"full"})}>{dayLabel(date,new Date(),dateLocale(),{today:t("today"),yesterday:t("yesterday")})}</time></div>;
 }
 function WorkspaceAvatar({name}:{name:string}){const parts=name.trim().split(/\s+/).filter(Boolean);const initials=(parts.length>1?parts.map(part=>part[0]).join(""):parts[0]?.slice(0,2)||"LB").slice(0,2).toUpperCase();return <span className="workspace-avatar" aria-hidden="true">{initials}</span>}
 function modeLabel(mode:ComputerMode){return mode==="team"?t("sharedComputer"):t("privateComputer")}
@@ -217,6 +226,20 @@ export function App(){
   const [slashIndex,setSlashIndex]=useState(0);
   const [slashDismissed,setSlashDismissed]=useState(false);
   useEffect(()=>{setSlashIndex(0);setSlashDismissed(false)},[draft]);
+  // Who answers a group message is decided by the server; here it is only
+  // typed. The `@` list opens on `@`, closes on the first space, and remembers
+  // nothing, because choosing who should talk must never feel like setup.
+  const [mentionIndex,setMentionIndex]=useState(0);
+  const [mentionDismissed,setMentionDismissed]=useState(false);
+  const [caretAt,setCaretAt]=useState(0);
+  const composerRef=useRef<HTMLTextAreaElement|null>(null);
+  const [hostMenuOpen,setHostMenuOpen]=useState(false);
+  useEffect(()=>{setMentionIndex(0);setMentionDismissed(false);setHostMenuOpen(false)},[draft,activeRoomId]);
+  useEffect(()=>{setCaretAt(current=>current>draft.length?draft.length:current)},[draft]);
+  const mentionQuery=activeRoom&&!mentionDismissed?mentionToken(draft,caretAt):null;
+  const mentionList=mentionQuery===null||!activeRoom?[]:mentionChoices(mentionQuery,activeRoom.members,t("everyoneMention"));
+  const roomHostId=activeRoom?activeRoom.hostBotId||activeRoom.members[0]?.id||null:null;
+  const roomHost=activeRoom?.members.find(member=>member.id===roomHostId)||null;
   const slashToken=draft.trimStart().split(/\s/,1)[0].slice(1).toLowerCase();
   const slashSuggestions=!slashDismissed&&/^\/[^\s]*$/.test(draft.trimStart())
     ? [{name:"goal",description:t("goalCommandHint"),kind:t("slashMode")},...fileSkills.map(skill=>({...skill,kind:t("slashFileSkill")}))].filter(skill=>!slashToken||skill.name.startsWith(slashToken)).slice(0,8)
@@ -290,7 +313,12 @@ export function App(){
   useEffect(()=>{if(!handingOff)return;handoffAtRef.current=Date.now();const timer=setTimeout(()=>{expectedHolderRef.current=null;setHandingOff(false)},HANDOFF_MS);return()=>clearTimeout(timer)},[handingOff]);
   useEffect(()=>{const frame=desktopFrameRef.current;if(!frame?.contentWindow||!screenUrl)return;frame.contentWindow.postMessage({type:"lazyboy-view-only",viewOnly:!desktopInteractive},location.origin)},[desktopInteractive,screenUrl,desktopReady]);
   useEffect(()=>{const listener=(event:MessageEvent)=>{if(event.origin!==location.origin||event.source!==desktopFrameRef.current?.contentWindow||event.data?.type!=="lazyboy-request-control"||!paneBotId)return;if(computer.sharedInput){pushViewOnly(!desktopInteractive);return}void setControl("user")};window.addEventListener("message",listener);return()=>window.removeEventListener("message",listener)},[paneBotId,computer.sharedInput,desktopInteractive]);
-  useEffect(()=>{const close=(event:MouseEvent)=>{const target=event.target;if(target instanceof Element&&target.closest(".create-menu-wrap,.account-wrap,.session-picker,.context-menu,.plus-menu-wrap"))return;setContext(null);setRoomContext(null);setSessionMenuOpen(false);setAccountOpen(false);setCreateMenuOpen(false);setPlusOpen(false)};window.addEventListener("click",close);return()=>window.removeEventListener("click",close)},[]);
+  async function setRoomHost(botId:string){
+    setHostMenuOpen(false);
+    if(!activeRoom||botId===roomHostId)return;
+    try{await api<Room>(`/api/rooms/${activeRoom.id}`,{method:"PATCH",body:JSON.stringify({hostBotId:botId})});await loadBots()}catch(error){setError(localizeError(error instanceof Error?error.message:t("operationFailed")))}
+  }
+  useEffect(()=>{const close=(event:MouseEvent)=>{const target=event.target;if(target instanceof Element&&target.closest(".create-menu-wrap,.account-wrap,.session-picker,.context-menu,.plus-menu-wrap,.host-chip-wrap"))return;setContext(null);setRoomContext(null);setSessionMenuOpen(false);setAccountOpen(false);setCreateMenuOpen(false);setPlusOpen(false);setHostMenuOpen(false)};window.addEventListener("click",close);return()=>window.removeEventListener("click",close)},[]);
   useEffect(()=>{const onKey=(event:KeyboardEvent)=>{if(event.key!=="Escape")return;setAccountOpen(false);setAccountDialog(null);setCreateMenuOpen(false);setPlusOpen(false);setTeachOpen(false);setEditingSkillId(null);setSessionMenuOpen(false);setContext(null);setRoomContext(null)};window.addEventListener("keydown",onKey);return()=>window.removeEventListener("keydown",onKey)},[]);
   useEffect(()=>{setWorkspaceName(name=>isDefaultWorkspaceName(name)?t("localWorkspace"):name)},[locale]);
   useEffect(()=>{localStorage.setItem(WORKSPACE_STORE,JSON.stringify({name:workspaceName,showHidden}))},[workspaceName,showHidden]);
@@ -365,7 +393,8 @@ export function App(){
     })}finally{sendingRef.current=false;setSendingMessage(false)}
   }
 
-  function composerKeyDown(event:ReactKeyboardEvent<HTMLTextAreaElement>){if(event.nativeEvent.isComposing||event.key==="Process")return;if(slashSuggestions.length){if(event.key==="Escape"){event.preventDefault();setSlashDismissed(true);return}if(event.key==="ArrowDown"||event.key==="ArrowUp"){event.preventDefault();setSlashIndex(index=>(index+(event.key==="ArrowDown"?1:slashSuggestions.length-1))%slashSuggestions.length);return}if(event.key==="Tab"||(event.key==="Enter"&&!event.shiftKey)){event.preventDefault();setDraft(`/${slashSuggestions[slashIndex%slashSuggestions.length].name} `);return}}const history=sentHistoryRef.current;if(event.key==="ArrowUp"&&history.length>0&&(!event.currentTarget.value.includes("\n")||event.currentTarget.selectionStart===0)){event.preventDefault();if(historyIndexRef.current===null){historyDraftRef.current=draft;historyIndexRef.current=history.length-1}else historyIndexRef.current=Math.max(0,historyIndexRef.current-1);setDraft(history[historyIndexRef.current]);return}if(event.key==="ArrowDown"&&historyIndexRef.current!==null&&(!event.currentTarget.value.includes("\n")||event.currentTarget.selectionEnd===event.currentTarget.value.length)){event.preventDefault();if(historyIndexRef.current<history.length-1){historyIndexRef.current+=1;setDraft(history[historyIndexRef.current])}else{historyIndexRef.current=null;setDraft(historyDraftRef.current)}return}if(event.key==="Enter"&&!event.shiftKey){event.preventDefault();if(sendingRef.current||busy)return;event.currentTarget.form?.requestSubmit()}}
+  function pickMention(choice:{name:string}){const next=acceptMention(draft,caretAt,choice.name);setDraft(next.text);setCaretAt(next.caret);requestAnimationFrame(()=>composerRef.current?.focus())}
+  function composerKeyDown(event:ReactKeyboardEvent<HTMLTextAreaElement>){if(event.nativeEvent.isComposing||event.key==="Process")return;if(mentionList.length){if(event.key==="Escape"){event.preventDefault();setMentionDismissed(true);return}if(event.key==="ArrowDown"||event.key==="ArrowUp"){event.preventDefault();setMentionIndex(index=>(index+(event.key==="ArrowDown"?1:mentionList.length-1))%mentionList.length);return}if(event.key==="Tab"||(event.key==="Enter"&&!event.shiftKey)){event.preventDefault();pickMention(mentionList[mentionIndex%mentionList.length]);return}}if(slashSuggestions.length){if(event.key==="Escape"){event.preventDefault();setSlashDismissed(true);return}if(event.key==="ArrowDown"||event.key==="ArrowUp"){event.preventDefault();setSlashIndex(index=>(index+(event.key==="ArrowDown"?1:slashSuggestions.length-1))%slashSuggestions.length);return}if(event.key==="Tab"||(event.key==="Enter"&&!event.shiftKey)){event.preventDefault();setDraft(`/${slashSuggestions[slashIndex%slashSuggestions.length].name} `);return}}const history=sentHistoryRef.current;if(event.key==="ArrowUp"&&history.length>0&&(!event.currentTarget.value.includes("\n")||event.currentTarget.selectionStart===0)){event.preventDefault();if(historyIndexRef.current===null){historyDraftRef.current=draft;historyIndexRef.current=history.length-1}else historyIndexRef.current=Math.max(0,historyIndexRef.current-1);setDraft(history[historyIndexRef.current]);return}if(event.key==="ArrowDown"&&historyIndexRef.current!==null&&(!event.currentTarget.value.includes("\n")||event.currentTarget.selectionEnd===event.currentTarget.value.length)){event.preventDefault();if(historyIndexRef.current<history.length-1){historyIndexRef.current+=1;setDraft(history[historyIndexRef.current])}else{historyIndexRef.current=null;setDraft(historyDraftRef.current)}return}if(event.key==="Enter"&&!event.shiftKey){event.preventDefault();if(sendingRef.current||busy)return;event.currentTarget.form?.requestSubmit()}}
   function selectSession(id:string){setActiveSessionId(id);setSessionMenuOpen(false);if(sessionStoreKey)writeSessionStore(sessionStoreKey,id)}
   async function createSession(){if(!sessionsPath||!sessionStoreKey)return;setSessionMenuOpen(false);setBusy(true);setError(null);try{const session=await api<Session>(sessionsPath,{method:"POST",body:JSON.stringify({title:t("newConversation")})});writeSessionStore(sessionStoreKey,session.id);const next=await api<Session[]>(sessionsPath);setSessions(next);setActiveSessionId(session.id);setMessages([])}catch(e){setError(e instanceof Error?localizeError(e.message):t("operationFailed"))}finally{setBusy(false)}}
   // A run that stopped to ask keeps its harness state, so the answer is just a
@@ -525,14 +554,14 @@ export function App(){
     </aside>
 
     <main className="chat-panel">
-      <header className="topbar"><button type="button" className="icon-button mobile-menu" aria-label={t("chooseBot")} aria-expanded={mobileNav} aria-controls="conversation-sidebar" onClick={()=>setMobileNav(v=>!v)}><UseAnimations animation={menu} size={18} strokeColor="var(--ink)"/></button>{activeRoom?<><AvatarStack members={activeRoom.members} size={32} online thinkingIds={busyMembers.map(member=>member.id)}/><strong>{activeRoom.name}</strong><SessionMenu sessions={sessions} activeSessionId={activeSessionId} open={sessionMenuOpen} setOpen={setSessionMenuOpen} busy={busy} onSelect={selectSession} onCreate={createSession} onDelete={id=>{setSessionMenuOpen(false);setSessionToDelete(id)}} onClear={()=>{setSessionMenuOpen(false);setClearOpen(true)}}/><span className="grow"/>{topTools}</>:active?<><Avatar lookId={active.id} name={active.name} color={active.avatarColor} shape={active.avatarShape} active online/><strong>{active.name}</strong><SessionMenu sessions={sessions} activeSessionId={activeSessionId} open={sessionMenuOpen} setOpen={setSessionMenuOpen} busy={busy} onSelect={selectSession} onCreate={createSession} onDelete={id=>{setSessionMenuOpen(false);setSessionToDelete(id)}} onClear={()=>{setSessionMenuOpen(false);setClearOpen(true)}}/><span className="grow"/>{topTools}</>:<><strong>{t("chooseBot")}</strong><span className="grow"/>{topTools}</>}</header>
+      <header className="topbar"><button type="button" className="icon-button mobile-menu" aria-label={t("chooseBot")} aria-expanded={mobileNav} aria-controls="conversation-sidebar" onClick={()=>setMobileNav(v=>!v)}><UseAnimations animation={menu} size={18} strokeColor="var(--ink)"/></button>{activeRoom?<><AvatarStack members={activeRoom.members} size={32} online thinkingIds={busyMembers.map(member=>member.id)}/><strong>{activeRoom.name}</strong><span className="host-chip-wrap" onClick={event=>event.stopPropagation()}><button type="button" className="host-chip" title={t("hostHint")} aria-haspopup="menu" aria-expanded={hostMenuOpen} onClick={()=>setHostMenuOpen(v=>!v)}><Megaphone size={13}/><span>{roomHost?roomHost.name:t("hostBadge")}</span></button>{hostMenuOpen&&<div className="host-menu" role="menu"><small className="host-menu-label">{t("hostMenuLabel")}</small>{activeRoom.members.map(member=><button type="button" role="menuitemradio" aria-checked={member.id===roomHostId} key={member.id} onClick={()=>void setRoomHost(member.id)}><Avatar lookId={member.id} name={member.name} color={member.avatarColor} shape={member.avatarShape} size={18}/><span>{member.name}</span>{member.id===roomHostId&&<b className="host-flag">{t("hostBadge")}</b>}</button>)}</div>}</span><SessionMenu sessions={sessions} activeSessionId={activeSessionId} open={sessionMenuOpen} setOpen={setSessionMenuOpen} busy={busy} onSelect={selectSession} onCreate={createSession} onDelete={id=>{setSessionMenuOpen(false);setSessionToDelete(id)}} onClear={()=>{setSessionMenuOpen(false);setClearOpen(true)}}/><span className="grow"/>{topTools}</>:active?<><Avatar lookId={active.id} name={active.name} color={active.avatarColor} shape={active.avatarShape} active online/><strong>{active.name}</strong><SessionMenu sessions={sessions} activeSessionId={activeSessionId} open={sessionMenuOpen} setOpen={setSessionMenuOpen} busy={busy} onSelect={selectSession} onCreate={createSession} onDelete={id=>{setSessionMenuOpen(false);setSessionToDelete(id)}} onClear={()=>{setSessionMenuOpen(false);setClearOpen(true)}}/><span className="grow"/>{topTools}</>:<><strong>{t("chooseBot")}</strong><span className="grow"/>{topTools}</>}</header>
       {callOpen&&voiceSettings?.enabled&&active&&activeSessionId&&!activeRoomId?<CallOverlay bot={active} sessionId={activeSessionId} takeover={computer.takeoverRequested||(!computer.sharedInput&&computer.controlHolder==="user")} onHangUp={()=>setCallOpen(false)} onTakeOver={()=>{setRightPart("computer");setRightCollapsed(false);setComputerOpen(true);if(active&&!computer.sharedInput)void setControl("user",active.id)}}/>:null}
-      <div className="messages">{(activeRoom||active)&&messages.length===0?<div className="welcome">{activeRoom?<AvatarStack members={activeRoom.members} size={56} online/>:<Avatar lookId={active!.id} name={active!.name} color={active!.avatarColor} shape={active!.avatarShape} active online size={64}/>}<h1>{activeRoom?t("startRoomDiscussion",{name:activeRoom.name}):t("startBotWork",{name:active!.name})}</h1><p>{activeRoom?t("roomWillReply",{names:listJoin(activeRoom.members.map(member=>member.name))}):active!.description||t("botWelcome")}</p></div>:messages.map(message=>{const spoken=message.role!=="user"&&Boolean(activeRoom);const speakerName=message.speakerName||(spoken?paneBot?.name:undefined);const speakerShape=(message.speakerShape||paneBot?.avatarShape||"blob") as AvatarShape;const files=messageFiles(message.blocks);const chips=chipBlocks(message.blocks);const hideBody=isAutoAttachCaption(message.body,files)||isAutoScheduleCaption(message.body,chips);return <div key={message.id} className={`message ${message.role} ${spoken?"spoken":""} ${files.length?"with-files":""}`}>{spoken&&<span className="msg-avatar"><Avatar lookId={message.speakerBotId||paneBot?.id||undefined} name={speakerName||"agent"} color={message.speakerColor||undefined} shape={speakerShape} size={22}/></span>}{spoken&&<b className="speaker" style={{color:message.speakerColor||undefined}}>{speakerName}</b>}{files.length>0&&<div className="msg-attachments">{files.map(file=><FileCard key={file.name} file={file}/>)}</div>}{chips.map((chip,index)=>chip.kind==="error"?<div className="login-chip error-chip" key={`${message.id}-error-${index}`}><div className="login-label">{errorTitle(chip.code)}</div><div className="error-actions">{errorActions(chip.code).map(next=>next==="retry"?<button type="button" className="primary" key="retry" title={t("errorRetryHint")} disabled={busy||!chip.runId||Boolean(retriedRuns[chip.runId])} onClick={()=>void retryRun(chip.runId)}>{retriedRuns[chip.runId||""]?t("errorRetried"):t("errorRetry")}</button>:next==="screen"?<button type="button" key="screen" onClick={()=>void openLoginScreen()}>{t("loginOpenScreen")}</button>:<button type="button" key="settings" onClick={()=>openAccount("model")}>{t("errorOpenSettings")}</button>)}<RunProbe runId={chip.runId||null} align="end" label={t("errorDetails")}><span className="error-probe" title={t("errorDetails")}><Info/></span></RunProbe></div></div>:chip.kind==="resume"?<div className="login-chip resume-chip" key={`${message.id}-resume-${index}`}><div className="login-label">{resumeTitle(chip.reason)}</div>{(chip.limit||0)>0?<div className="login-why">{t("resumeProgress",{turns:chip.turns||0,limit:chip.limit||0})}</div>:null}{resumedChips[message.id]||(message.seq??0)<lastAssistantSeq?null:<div className="resume-actions"><button type="button" className="primary" disabled={busy} onClick={()=>void continueRun(message.id)}>{t("resumeContinue")}</button><button type="button" className="outline" disabled={busy} onClick={()=>setResumedChips(current=>({...current,[message.id]:true}))}>{t("resumeStop")}</button></div>}</div>:chip.kind==="login"?<div className="login-chip" key={`${message.id}-login-${index}`}><div className="login-label">{t("loginNeedsYou")}</div><div className="login-site">{chip.site||message.body}</div>{chip.why?<div className="login-why">{t("loginWhy",{why:chip.why})}</div>:null}<button type="button" className="primary" onClick={()=>void openLoginScreen()}>{t("loginOpenScreen")}</button></div>:chip.kind==="schedule"?<div className="sched-chip" key={`${message.id}-sched-${index}`}><div className="sched-label">{t("scheduleChip")}</div><strong>{chip.name}</strong><small>{scheduleWhen(chip.cron,chip.human)}</small></div>:<div className="sched-chip" key={`${message.id}-run-${index}`}><div className="sched-label">{t("scheduleRunChip")}</div><strong>{chip.name}</strong><small>{scheduleWhen(chip.cron,chip.human)}</small></div>)}{!hideBody&&(message.role==="assistant"?<div className="message-stack"><div className="message-body md"><ChatMarkdown>{message.body}</ChatMarkdown></div>{message.body.trim()?<CopyMessageButton text={message.body}/>:null}{message.runId&&<RunProbe runId={message.runId} label={t("messageRunDetails")}><span className="message-run-details"><Info/>{t("messageRunDetails")}</span></RunProbe>}</div>:<span className="message-body">{message.body}</span>)}{!hideBody&&message.body.trim()&&<button type="button" className={`remember-msg ${remembered[message.id]?"saved":""}`} title={remembered[message.id]?t("remembered"):t("remember")} disabled={!!remembered[message.id]} onClick={()=>void rememberMessage(message)}><UseAnimations animation={bookmark} size={14} strokeColor="var(--muted)"/></button>}<MessageTime value={message.createdAt}/></div>})}{pausedForUser&&paneBot&&<div className="pause-banner" role="status"><span>{computer.sharedInput?t("sharedNeedsUser",{name:paneBot.name}):computer.controlHolder==="user"?t("pausedUserControl",{name:paneBot.name}):t("pausedNeedsUser",{name:paneBot.name})}{(computer.queuedRuns||0)>0&&<> {t("queuedMessages",{count:computer.queuedRuns||0})}</>}</span>{computer.sharedInput||computer.controlHolder==="user"?<button type="button" className="primary" disabled={busy||controlBusy} onClick={()=>void setControl("none",paneBot.id)}>{computer.sharedInput?t("doneContinue"):t("releaseAndContinue")}</button>:<button type="button" className="primary" disabled={busy||controlBusy} onClick={()=>void setControl("user",paneBot.id)}>{t("takeOverNow")}</button>}</div>}{teaching&&active&&<div className="teach-banner recording" role="status"><span><i className="record-dot live"/>{t("teachingLive",{goal:teaching.goal})}<small>{t("teachingHint")}{teaching.eventCount>0&&<> · {t("teachingCaptured",{count:teaching.eventCount})}</>}</small></span><button type="button" className="primary" disabled={busy} onClick={()=>void stopTeaching()}>{t("finishDemo")}</button><button type="button" className="outline" disabled={busy} onClick={()=>void cancelTeaching()}>{t("cancel")}</button></div>}{drafting&&<div className="teach-banner" role="status"><UseAnimations animation={loading} size={18} wrapperStyle={{display:"inline-block",verticalAlign:"middle"}}/><span>{t("distilling",{goal:drafting.goal})}</span></div>}{skillDraft&&active&&<SkillDraftCard key={skillDraft.id} skill={skillDraft} busy={busy} onSave={(name,playbook)=>void saveSkill(skillDraft,name,playbook)} onTest={(name,playbook)=>void testSkill(skillDraft,name,playbook)} onDiscard={()=>void discardSkill(skillDraft)} onEdit={()=>setEditingSkillId(skillDraft.id)} onExport={(name,playbook)=>downloadSkill(name,skillDraft.goal,playbook)}/>}{Object.values(replyDrafts).filter(reply=>reply.text&&(!reply.messageId||!messages.some(message=>message.id===reply.messageId))).map(reply=>{const speaker=bots.find(bot=>bot.id===reply.botId);return <div className={`message assistant ${activeRoom?"spoken":""}`} key={reply.runId} aria-busy={!reply.messageId}>{activeRoom&&speaker&&<><span className="msg-avatar"><Avatar lookId={speaker.id} name={speaker.name} color={speaker.avatarColor} shape={speaker.avatarShape} online/></span><span className="speaker">{speaker.name}</span></>}<div className="message-stack"><div className="message-body md"><ChatMarkdown>{reply.text}</ChatMarkdown></div></div></div>})}<div ref={messageEndRef} aria-hidden="true"/></div>
+      <div className="messages">{(activeRoom||active)&&messages.length===0?<div className="welcome">{activeRoom?<AvatarStack members={activeRoom.members} size={56} online/>:<Avatar lookId={active!.id} name={active!.name} color={active!.avatarColor} shape={active!.avatarShape} active online size={64}/>}<h1>{activeRoom?t("startRoomDiscussion",{name:activeRoom.name}):t("startBotWork",{name:active!.name})}</h1><p>{activeRoom?t("roomWillReply",{names:listJoin(activeRoom.members.map(member=>member.name))}):active!.description||t("botWelcome")}</p></div>:messages.map((message,index)=>{const spoken=message.role!=="user"&&Boolean(activeRoom);const speakerName=message.speakerName||(spoken?paneBot?.name:undefined);const speakerShape=(message.speakerShape||paneBot?.avatarShape||"blob") as AvatarShape;const files=messageFiles(message.blocks);const chips=chipBlocks(message.blocks);const hideBody=isAutoAttachCaption(message.body,files)||isAutoScheduleCaption(message.body,chips);const previous=index>0?messages[index-1]:null;const newDay=!previous||!sameDay(previous.createdAt,message.createdAt);return <Fragment key={message.id}>{newDay&&<DayDivider value={message.createdAt}/>}<div className={`message ${message.role} ${spoken?"spoken":""} ${files.length?"with-files":""}`}>{spoken&&<span className="msg-avatar"><Avatar lookId={message.speakerBotId||paneBot?.id||undefined} name={speakerName||"agent"} color={message.speakerColor||undefined} shape={speakerShape} size={22}/></span>}{spoken&&<b className="speaker" style={{color:message.speakerColor||undefined}}>{speakerName}</b>}{files.length>0&&<div className="msg-attachments">{files.map(file=><FileCard key={file.name} file={file}/>)}</div>}{chips.map((chip,index)=>chip.kind==="error"?<div className="login-chip error-chip" key={`${message.id}-error-${index}`}><div className="login-label">{errorTitle(chip.code)}</div><div className="error-actions">{errorActions(chip.code).map(next=>next==="retry"?<button type="button" className="primary" key="retry" title={t("errorRetryHint")} disabled={busy||!chip.runId||Boolean(retriedRuns[chip.runId])} onClick={()=>void retryRun(chip.runId)}>{retriedRuns[chip.runId||""]?t("errorRetried"):t("errorRetry")}</button>:next==="screen"?<button type="button" key="screen" onClick={()=>void openLoginScreen()}>{t("loginOpenScreen")}</button>:<button type="button" key="settings" onClick={()=>openAccount("model")}>{t("errorOpenSettings")}</button>)}<RunProbe runId={chip.runId||null} align="end" label={t("errorDetails")}><span className="error-probe" title={t("errorDetails")}><Info/></span></RunProbe></div></div>:chip.kind==="resume"?<div className="login-chip resume-chip" key={`${message.id}-resume-${index}`}><div className="login-label">{resumeTitle(chip.reason)}</div>{(chip.limit||0)>0?<div className="login-why">{t("resumeProgress",{turns:chip.turns||0,limit:chip.limit||0})}</div>:null}{resumedChips[message.id]||(message.seq??0)<lastAssistantSeq?null:<div className="resume-actions"><button type="button" className="primary" disabled={busy} onClick={()=>void continueRun(message.id)}>{t("resumeContinue")}</button><button type="button" className="outline" disabled={busy} onClick={()=>setResumedChips(current=>({...current,[message.id]:true}))}>{t("resumeStop")}</button></div>}</div>:chip.kind==="login"?<div className="login-chip" key={`${message.id}-login-${index}`}><div className="login-label">{t("loginNeedsYou")}</div><div className="login-site">{chip.site||message.body}</div>{chip.why?<div className="login-why">{t("loginWhy",{why:chip.why})}</div>:null}<button type="button" className="primary" onClick={()=>void openLoginScreen()}>{t("loginOpenScreen")}</button></div>:chip.kind==="schedule"?<div className="sched-chip" key={`${message.id}-sched-${index}`}><div className="sched-label">{t("scheduleChip")}</div><strong>{chip.name}</strong><small>{scheduleWhen(chip.cron,chip.human)}</small></div>:<div className="sched-chip" key={`${message.id}-run-${index}`}><div className="sched-label">{t("scheduleRunChip")}</div><strong>{chip.name}</strong><small>{scheduleWhen(chip.cron,chip.human)}</small></div>)}{!hideBody&&(message.role==="assistant"?<div className="message-stack"><div className="message-body md"><ChatMarkdown>{message.body}</ChatMarkdown></div>{message.body.trim()?<CopyMessageButton text={message.body}/>:null}{message.runId&&<RunProbe runId={message.runId} label={t("messageRunDetails")}><span className="message-run-details"><Info/>{t("messageRunDetails")}</span></RunProbe>}</div>:<span className="message-body">{message.body}</span>)}{!hideBody&&message.body.trim()&&<button type="button" className={`remember-msg ${remembered[message.id]?"saved":""}`} title={remembered[message.id]?t("remembered"):t("remember")} disabled={!!remembered[message.id]} onClick={()=>void rememberMessage(message)}><UseAnimations animation={bookmark} size={14} strokeColor="var(--muted)"/></button>}<MessageTime value={message.createdAt}/>{message.replyBots&&message.replyBots.length>0&&<div className="route-note">{message.role==="user"?t("routedTo",{names:listJoin(message.replyBots.map(reply=>reply.name))}):t("handedTo",{name:message.replyBots[0].name})}</div>}</div></Fragment>})}{pausedForUser&&paneBot&&<div className="pause-banner" role="status"><span>{computer.sharedInput?t("sharedNeedsUser",{name:paneBot.name}):computer.controlHolder==="user"?t("pausedUserControl",{name:paneBot.name}):t("pausedNeedsUser",{name:paneBot.name})}{(computer.queuedRuns||0)>0&&<> {t("queuedMessages",{count:computer.queuedRuns||0})}</>}</span>{computer.sharedInput||computer.controlHolder==="user"?<button type="button" className="primary" disabled={busy||controlBusy} onClick={()=>void setControl("none",paneBot.id)}>{computer.sharedInput?t("doneContinue"):t("releaseAndContinue")}</button>:<button type="button" className="primary" disabled={busy||controlBusy} onClick={()=>void setControl("user",paneBot.id)}>{t("takeOverNow")}</button>}</div>}{teaching&&active&&<div className="teach-banner recording" role="status"><span><i className="record-dot live"/>{t("teachingLive",{goal:teaching.goal})}<small>{t("teachingHint")}{teaching.eventCount>0&&<> · {t("teachingCaptured",{count:teaching.eventCount})}</>}</small></span><button type="button" className="primary" disabled={busy} onClick={()=>void stopTeaching()}>{t("finishDemo")}</button><button type="button" className="outline" disabled={busy} onClick={()=>void cancelTeaching()}>{t("cancel")}</button></div>}{drafting&&<div className="teach-banner" role="status"><UseAnimations animation={loading} size={18} wrapperStyle={{display:"inline-block",verticalAlign:"middle"}}/><span>{t("distilling",{goal:drafting.goal})}</span></div>}{skillDraft&&active&&<SkillDraftCard key={skillDraft.id} skill={skillDraft} busy={busy} onSave={(name,playbook)=>void saveSkill(skillDraft,name,playbook)} onTest={(name,playbook)=>void testSkill(skillDraft,name,playbook)} onDiscard={()=>void discardSkill(skillDraft)} onEdit={()=>setEditingSkillId(skillDraft.id)} onExport={(name,playbook)=>downloadSkill(name,skillDraft.goal,playbook)}/>}{Object.values(replyDrafts).filter(reply=>reply.text&&(!reply.messageId||!messages.some(message=>message.id===reply.messageId))).map(reply=>{const speaker=bots.find(bot=>bot.id===reply.botId);return <div className={`message assistant ${activeRoom?"spoken":""}`} key={reply.runId} aria-busy={!reply.messageId}>{activeRoom&&speaker&&<><span className="msg-avatar"><Avatar lookId={speaker.id} name={speaker.name} color={speaker.avatarColor} shape={speaker.avatarShape} online/></span><span className="speaker">{speaker.name}</span></>}<div className="message-stack"><div className="message-body md"><ChatMarkdown>{reply.text}</ChatMarkdown></div></div></div>})}<div ref={messageEndRef} aria-hidden="true"/></div>
       <div className={`composer-dock ${statusMembers.length?"has-status":""}`}>
       {error&&<div className="error-banner"><span>{error}</span><button onClick={()=>setError(null)}><X/></button></div>}
       {otherSessionBusy&&<div className="queue-hint">{t("anotherConversationQueued")}</div>}
       {statusMembers.map(member=>{const step=computer.busyStep&&member.id===computer.botId?computer.busyStep:null;const transition=isTransitionStep(step);const label=t("working",{name:member.name});return <div className="thinking-row" key={member.id}><RunProbe runId={member.id===computer.botId?computer.busyRunId:null}><Avatar lookId={member.id} name={member.name} color={member.avatarColor} shape={member.avatarShape} thinking online/></RunProbe><span className="working-copy"><span className="working-label">{label}</span>{!transition&&step?<span className="working-step">{localizeStep(step)}</span>:null}</span></div>})}
-      <form className={`composer ${pendingFiles.length?"has-files":""}`} onSubmit={send} onDragOver={event=>{event.preventDefault()}} onDrop={event=>{event.preventDefault();if(event.dataTransfer.files.length)addPendingFiles(event.dataTransfer.files)}}><div className="plus-menu-wrap" onClick={event=>event.stopPropagation()}><button type="button" className={`composer-plus ${plusOpen?"open":""}`} disabled={!activeSessionId} title={t("moreActions")} aria-label={t("moreActions")} aria-haspopup="menu" aria-expanded={plusOpen} onClick={()=>setPlusOpen(v=>!v)}><Plus/></button>{plusOpen&&<div className="plus-menu" role="menu"><button type="button" role="menuitem" disabled={!activeSessionId||Boolean(teaching)} title={t("attachFileHint")} onClick={()=>{setPlusOpen(false);attachRef.current?.click()}}><Paperclip/>{t("attachFile")}</button><button type="button" role="menuitem" disabled={!active||Boolean(teaching)||Boolean(drafting)} title={active?t("teachTaskHint"):t("teachNeedsBot")} onClick={()=>{setPlusOpen(false);setTeachOpen(true)}}><i className="record-dot"/>{t("teachTask")}</button><button type="button" role="menuitem" disabled={!active} title={t("importSkillHint")} onClick={()=>{setPlusOpen(false);importRef.current?.click()}}><Upload/>{t("importSkill")}</button>{savedSkills.length>0&&<><hr/><div className="plus-menu-skills"><small className="plus-menu-label">{t("taughtSkills")}{savedSkills.length>5?` · ${savedSkills.length}`:""}</small>{savedSkills.length>=6&&<input className="plus-menu-search" value={skillQuery} onChange={e=>setSkillQuery(e.target.value)} placeholder={t("searchSkills")} aria-label={t("searchSkills")} onClick={e=>e.stopPropagation()}/>}<div className="plus-menu-skill-list">{listedSkills.map(skill=><div className="plus-menu-skill" key={skill.id}><button type="button" role="menuitem" title={t("runSkillNamed",{name:skill.name})+(skill.playbook.whenToUse?`\n${skill.playbook.whenToUse}`:"")} onClick={()=>runSkill(skill)}><Sparkle/>{skill.name}</button><button type="button" className="skill-edit" title={t("exportSkillHint")} aria-label={t("exportSkill")} onClick={()=>downloadSkill(skill.name,skill.goal,skill.playbook)}><Download/></button><button type="button" className="skill-edit" title={t("editSkill")} aria-label={t("editSkill")} onClick={()=>{setPlusOpen(false);setEditingSkillId(skill.id)}}><Pencil/></button></div>)}{listedSkills.length===0&&<small className="plus-menu-empty">{t("noMatchingSkills")}</small>}</div></div></>}</div>}</div><input ref={importRef} className="skill-import-input" type="file" accept="application/json,.json" tabIndex={-1} aria-hidden="true" onChange={event=>{const file=event.target.files?.[0];event.currentTarget.value="";if(file)void importSkillFile(file)}}/><input ref={attachRef} className="skill-import-input attach-input" type="file" multiple accept={ATTACH_ACCEPT} tabIndex={-1} aria-hidden="true" onChange={event=>{const files=[...event.target.files||[]];event.currentTarget.value="";if(files.length)addPendingFiles(files)}}/>{pendingFiles.length>0&&<div className="composer-files">{pendingFiles.map(item=><FileCard key={item.id} file={{name:item.file.name,size:item.file.size}} preview={item.preview} onRemove={()=>removePendingFile(item.id)}/>)}</div>}{slashSuggestions.length>0&&<div className="slash-suggestions" role="listbox" aria-label={t("slashList")}>{slashSuggestions.map((skill,index)=><button type="button" role="option" aria-selected={index===slashIndex} key={skill.name} onClick={()=>{setDraft(`/${skill.name} `);requestAnimationFrame(()=>document.querySelector<HTMLTextAreaElement>(".composer textarea")?.focus())}}><strong>/{skill.name}</strong><small>{skill.kind}</small><span>{skill.description}</span></button>)}</div>}<textarea rows={1} value={draft} onChange={e=>setDraft(e.target.value)} onKeyDown={composerKeyDown} onPaste={event=>{const files=event.clipboardData?.files;if(files&&files.length){event.preventDefault();addPendingFiles(files)}}} placeholder={teaching?t("teachingComposerHint"):activeSessionId&&chatName?t("messageTo",{name:chatName}):t("chooseConversationFirst")} disabled={!activeSessionId||Boolean(teaching)}/>{sessionBusy?<button type="button" className="send stop-send" title={t("stopConversation")} onClick={()=>void action(stopChat)}><Square/></button>:<button className="send" disabled={!activeSessionId||(!draft.trim()&&pendingFiles.length===0)||busy}><UseAnimations animation={sendingMessage?loading:arrowUp} size={20} strokeColor="var(--on-send)"/></button>}</form>
+      <form className={`composer ${pendingFiles.length?"has-files":""}`} onSubmit={send} onDragOver={event=>{event.preventDefault()}} onDrop={event=>{event.preventDefault();if(event.dataTransfer.files.length)addPendingFiles(event.dataTransfer.files)}}><div className="plus-menu-wrap" onClick={event=>event.stopPropagation()}><button type="button" className={`composer-plus ${plusOpen?"open":""}`} disabled={!activeSessionId} title={t("moreActions")} aria-label={t("moreActions")} aria-haspopup="menu" aria-expanded={plusOpen} onClick={()=>setPlusOpen(v=>!v)}><Plus/></button>{plusOpen&&<div className="plus-menu" role="menu"><button type="button" role="menuitem" disabled={!activeSessionId||Boolean(teaching)} title={t("attachFileHint")} onClick={()=>{setPlusOpen(false);attachRef.current?.click()}}><Paperclip/>{t("attachFile")}</button><button type="button" role="menuitem" disabled={!active||Boolean(teaching)||Boolean(drafting)} title={active?t("teachTaskHint"):t("teachNeedsBot")} onClick={()=>{setPlusOpen(false);setTeachOpen(true)}}><i className="record-dot"/>{t("teachTask")}</button><button type="button" role="menuitem" disabled={!active} title={t("importSkillHint")} onClick={()=>{setPlusOpen(false);importRef.current?.click()}}><Upload/>{t("importSkill")}</button>{savedSkills.length>0&&<><hr/><div className="plus-menu-skills"><small className="plus-menu-label">{t("taughtSkills")}{savedSkills.length>5?` · ${savedSkills.length}`:""}</small>{savedSkills.length>=6&&<input className="plus-menu-search" value={skillQuery} onChange={e=>setSkillQuery(e.target.value)} placeholder={t("searchSkills")} aria-label={t("searchSkills")} onClick={e=>e.stopPropagation()}/>}<div className="plus-menu-skill-list">{listedSkills.map(skill=><div className="plus-menu-skill" key={skill.id}><button type="button" role="menuitem" title={t("runSkillNamed",{name:skill.name})+(skill.playbook.whenToUse?`\n${skill.playbook.whenToUse}`:"")} onClick={()=>runSkill(skill)}><Sparkle/>{skill.name}</button><button type="button" className="skill-edit" title={t("exportSkillHint")} aria-label={t("exportSkill")} onClick={()=>downloadSkill(skill.name,skill.goal,skill.playbook)}><Download/></button><button type="button" className="skill-edit" title={t("editSkill")} aria-label={t("editSkill")} onClick={()=>{setPlusOpen(false);setEditingSkillId(skill.id)}}><Pencil/></button></div>)}{listedSkills.length===0&&<small className="plus-menu-empty">{t("noMatchingSkills")}</small>}</div></div></>}</div>}</div><input ref={importRef} className="skill-import-input" type="file" accept="application/json,.json" tabIndex={-1} aria-hidden="true" onChange={event=>{const file=event.target.files?.[0];event.currentTarget.value="";if(file)void importSkillFile(file)}}/><input ref={attachRef} className="skill-import-input attach-input" type="file" multiple accept={ATTACH_ACCEPT} tabIndex={-1} aria-hidden="true" onChange={event=>{const files=[...event.target.files||[]];event.currentTarget.value="";if(files.length)addPendingFiles(files)}}/>{pendingFiles.length>0&&<div className="composer-files">{pendingFiles.map(item=><FileCard key={item.id} file={{name:item.file.name,size:item.file.size}} preview={item.preview} onRemove={()=>removePendingFile(item.id)}/>)}</div>}{slashSuggestions.length>0&&<div className="slash-suggestions" role="listbox" aria-label={t("slashList")}>{slashSuggestions.map((skill,index)=><button type="button" role="option" aria-selected={index===slashIndex} key={skill.name} onClick={()=>{setDraft(`/${skill.name} `);requestAnimationFrame(()=>document.querySelector<HTMLTextAreaElement>(".composer textarea")?.focus())}}><strong>/{skill.name}</strong><small>{skill.kind}</small><span>{skill.description}</span></button>)}</div>}{mentionList.length>0&&<div className="slash-suggestions mention-suggestions" role="listbox" aria-label={t("mentionList")}>{mentionList.map((choice,index)=><button type="button" role="option" aria-selected={index===mentionIndex} key={choice.member?.id||"everyone"} onClick={()=>pickMention(choice)}>{choice.member&&<Avatar lookId={choice.member.id} name={choice.member.name} color={choice.member.avatarColor} shape={choice.member.avatarShape} size={18}/>}<strong>@{choice.name}</strong>{choice.member?null:<small>{t("mentionEveryoneHint")}</small>}</button>)}</div>}<textarea ref={composerRef} rows={1} value={draft} onChange={e=>{setDraft(e.target.value);setCaretAt(e.target.selectionStart??e.target.value.length)}} onSelect={e=>setCaretAt(e.currentTarget.selectionStart)} onKeyDown={composerKeyDown} onPaste={event=>{const files=event.clipboardData?.files;if(files&&files.length){event.preventDefault();addPendingFiles(files)}}} placeholder={teaching?t("teachingComposerHint"):activeSessionId&&chatName?t("messageTo",{name:chatName}):t("chooseConversationFirst")} disabled={!activeSessionId||Boolean(teaching)}/>{sessionBusy?<button type="button" className="send stop-send" title={t("stopConversation")} onClick={()=>void action(stopChat)}><Square/></button>:<button className="send" disabled={!activeSessionId||(!draft.trim()&&pendingFiles.length===0)||busy}><UseAnimations animation={sendingMessage?loading:arrowUp} size={20} strokeColor="var(--on-send)"/></button>}</form>
       </div>
     </main>
 
@@ -925,7 +954,7 @@ function SkillEditDialog({skill,busy,close,save,test,remove,exportFile}:{skill:T
 }
 function ClipboardDialog({close,paste}:{close:()=>void;paste:(text:string)=>void}){const[text,setText]=useState("");return <div className="modal-backdrop"><div className="dialog compact"><div className="dialog-title"><h2>{t("pasteToRemoteComputer")}</h2><button onClick={close}><X/></button></div><p>{t("pasteRemoteHelp")}</p><textarea className="clipboard-text" autoFocus value={text} onChange={e=>setText(e.target.value)} placeholder={t("pasteTextPlaceholder")}/><div className="dialog-actions"><button className="outline" onClick={close}>{t("cancel")}</button><button className="primary" disabled={!text} onClick={()=>paste(text)}>{t("pasteIntoVnc")}</button></div></div></div>}
 function CreateDialog({close,created}:{close:()=>void;created:(bot:Bot)=>void}){const[name,setName]=useState("");const[mode,setMode]=useState<ComputerMode>("team");const[busy,setBusy]=useState(false);return <div className="modal-backdrop"><form className="dialog" onSubmit={async e=>{e.preventDefault();if(!name.trim())return;setBusy(true);try{created(await api<Bot>("/api/bots",{method:"POST",body:JSON.stringify({name:name.trim(),computerMode:mode})}))}finally{setBusy(false)}}}><div className="dialog-title"><h2>{t("addBot")}</h2><button type="button" onClick={close}><X/></button></div><label>{t("name")}<input autoFocus value={name} onChange={e=>setName(e.target.value)} placeholder={t("botNamePlaceholder")}/></label><div className="mode-grid"><button type="button" className={mode==="team"?"picked":""} onClick={()=>setMode("team")}><BotIcon/><strong>{t("sharedComputer")}</strong><small>{t("sharedComputerHint")}</small></button><button type="button" className={mode==="dedicated"?"picked":""} onClick={()=>setMode("dedicated")}><Computer/><strong>{t("privateComputer")}</strong><small>{t("privateComputerHint")}</small></button></div><div className="dialog-actions"><button type="button" className="outline" onClick={close}>{t("cancel")}</button><button className="primary" disabled={busy||!name.trim()}>{t("create")}</button></div></form></div>}
-function CreateGroupDialog({bots,close,created}:{bots:Bot[];close:()=>void;created:(room:Room)=>void}){const[name,setName]=useState("");const[selected,setSelected]=useState<string[]>([]);const[busy,setBusy]=useState(false);const visible=bots.filter(bot=>!bot.hidden);return <div className="modal-backdrop"><form className="dialog" onSubmit={async e=>{e.preventDefault();const groupName=name.trim();if(!groupName||selected.length<2)return;setBusy(true);try{created(await api<Room>("/api/rooms",{method:"POST",body:JSON.stringify({name:groupName,memberIds:selected})}))}finally{setBusy(false)}}}><div className="dialog-title"><h2>{t("addGroup")}</h2><button type="button" onClick={close}><X/></button></div><p className="dialog-lead">{t("groupDescription")}</p><label>{t("groupName")}<input autoFocus value={name} maxLength={30} onChange={e=>setName(e.target.value)} placeholder={t("groupNamePlaceholder")}/></label><fieldset className="group-picker"><legend>{t("chooseBots")}</legend>{visible.map(bot=><label key={bot.id}><input type="checkbox" checked={selected.includes(bot.id)} onChange={()=>setSelected(ids=>ids.includes(bot.id)?ids.filter(id=>id!==bot.id):[...ids,bot.id])}/><Avatar lookId={bot.id} name={bot.name} color={bot.avatarColor} shape={bot.avatarShape} online/><span>{bot.name}</span></label>)}</fieldset><div className="dialog-actions"><button type="button" className="outline" onClick={close}>{t("cancel")}</button><button className="primary" disabled={busy||!name.trim()||selected.length<2}>{busy?t("creating"):t("createGroup")}</button></div></form></div>}
+function CreateGroupDialog({bots,close,created}:{bots:Bot[];close:()=>void;created:(room:Room)=>void}){const[name,setName]=useState("");const[selected,setSelected]=useState<string[]>([]);const[busy,setBusy]=useState(false);const visible=bots.filter(bot=>!bot.hidden);return <div className="modal-backdrop"><form className="dialog" onSubmit={async e=>{e.preventDefault();const groupName=name.trim();if(!groupName||selected.length<2)return;setBusy(true);try{created(await api<Room>("/api/rooms",{method:"POST",body:JSON.stringify({name:groupName,memberIds:selected})}))}finally{setBusy(false)}}}><div className="dialog-title"><h2>{t("addGroup")}</h2><button type="button" onClick={close}><X/></button></div><p className="dialog-lead">{t("groupDescription")}</p><label>{t("groupName")}<input autoFocus value={name} maxLength={30} onChange={e=>setName(e.target.value)} placeholder={t("groupNamePlaceholder")}/></label><fieldset className="group-picker"><legend>{t("chooseBots")}</legend>{visible.map(bot=><label key={bot.id}><input type="checkbox" checked={selected.includes(bot.id)} onChange={()=>setSelected(ids=>ids.includes(bot.id)?ids.filter(id=>id!==bot.id):[...ids,bot.id])}/><Avatar lookId={bot.id} name={bot.name} color={bot.avatarColor} shape={bot.avatarShape} online/><span>{bot.name}</span></label>)}</fieldset>{selected.length>0&&<p className="dialog-note">{t("groupHostHint",{name:visible.find(bot=>bot.id===selected[0])?.name||""})}</p>}<div className="dialog-actions"><button type="button" className="outline" onClick={close}>{t("cancel")}</button><button className="primary" disabled={busy||!name.trim()||selected.length<2}>{busy?t("creating"):t("createGroup")}</button></div></form></div>}
 function RoomContextMenu({context,close,onDelete}:{context:{room:Room;x:number;y:number};close:()=>void;onDelete:()=>void}){return <div className="context-menu" style={{left:Math.min(context.x,window.innerWidth-220),top:Math.min(context.y,window.innerHeight-160)}} onClick={e=>e.stopPropagation()}><button className="danger-item" onClick={onDelete}><UseAnimations animation={trash2} size={15} strokeColor="var(--danger-soft)"/>{t("deleteGroup")}</button><button className="context-close" onClick={close}><X/></button></div>}
 function ConfirmRoomDelete({room,close,confirm}:{room:Room;close:()=>void;confirm:()=>void}){return <div className="modal-backdrop"><div className="dialog compact"><h2>{t("deleteNamed",{name:room.name})}</h2><p>{t("deleteGroupDescription")}</p><div className="dialog-actions"><button className="outline" onClick={close}>{t("cancel")}</button><button className="danger" onClick={confirm}>{t("deleteGroup")}</button></div></div></div>}
 function ConfirmDelete({bot,close,confirm}:{bot:Bot;close:()=>void;confirm:()=>void}){return <div className="modal-backdrop"><div className="dialog compact"><h2>{t("deleteNamed",{name:bot.name})}</h2><p>{bot.computerMode==="dedicated"?t("deleteDedicatedBotDescription"):t("deleteSharedBotDescription")}</p><div className="dialog-actions"><button className="outline" onClick={close}>{t("cancel")}</button><button className="danger" onClick={confirm}>{t("delete")}</button></div></div></div>}
diff --git a/apps/web/src/chat-time.ts b/apps/web/src/chat-time.ts
new file mode 100644
index 0000000..0f1b274
--- /dev/null
+++ b/apps/web/src/chat-time.ts
@@ -0,0 +1,54 @@
+/**
+ * How a chat shows when something was said: the day is written once, as a
+ * divider above the first message of that day, and each message carries only
+ * its clock time. A day is named the way people say it — 今天, 昨天 — and
+ * spelled out only when it is further away.
+ */
+
+export interface DayWords {
+  today: string;
+  yesterday: string;
+}
+
+/** Local calendar day, so two timestamps on the same date compare equal. */
+export function dayKey(value: string | Date): string {
+  const date = value instanceof Date ? value : new Date(value);
+  if (!Number.isFinite(date.getTime())) return "";
+  return `${date.getFullYear()}-${date.getMonth() + 1}-${date.getDate()}`;
+}
+
+export function sameDay(a: string | Date, b: string | Date): boolean {
+  const keyA = dayKey(a);
+  return keyA !== "" && keyA === dayKey(b);
+}
+
+/** Whole local days between two moments; negative when `date` is in the future. */
+function daysBefore(date: Date, now: Date): number {
+  const start = (value: Date) => new Date(value.getFullYear(), value.getMonth(), value.getDate()).getTime();
+  return Math.round((start(now) - start(date)) / 86_400_000);
+}
+
+/**
+ * The divider text for a day: 今天 / 昨天, then a weekday for the past week
+ * (people remember "Wednesday" before "the 3rd"), then a short date, and the
+ * year only when it is not this one.
+ */
+export function dayLabel(value: string | Date, now: Date, locale: string, words: DayWords): string {
+  const date = value instanceof Date ? value : new Date(value);
+  if (!Number.isFinite(date.getTime())) return "";
+  const ago = daysBefore(date, now);
+  if (ago === 0) return words.today;
+  if (ago === 1) return words.yesterday;
+  if (ago > 1 && ago < 7) return date.toLocaleDateString(locale, { weekday: "long" });
+  if (date.getFullYear() === now.getFullYear()) {
+    return date.toLocaleDateString(locale, { month: "numeric", day: "numeric", weekday: "short" });
+  }
+  return date.toLocaleDateString(locale, { year: "numeric", month: "numeric", day: "numeric" });
+}
+
+/** The clock time a message shows next to itself; the day lives in the divider. */
+export function clockTime(value: string | Date, locale: string): string {
+  const date = value instanceof Date ? value : new Date(value);
+  if (!Number.isFinite(date.getTime())) return "";
+  return date.toLocaleTimeString(locale, { hour: "2-digit", minute: "2-digit", hour12: false });
+}
diff --git a/apps/web/src/chat.css b/apps/web/src/chat.css
index 7959880..ad3bc17 100644
--- a/apps/web/src/chat.css
+++ b/apps/web/src/chat.css
@@ -77,3 +77,31 @@
 .message{padding-bottom:21px}
 .message-time{position:absolute;bottom:0;left:0;font-size:11px;line-height:17px;color:var(--muted);font-variant-numeric:tabular-nums}
 .message.user .message-time{left:auto;right:28px}
+
+/* The day is said once, centred above the first message of that day, so each
+   message only needs its clock time. */
+.day-divider{display:flex;justify-content:center;width:var(--chat-col);margin:6px auto -4px;user-select:none}
+.day-divider time{padding:3px 11px;border-radius:999px;background:rgba(255,255,255,.06);color:var(--muted);font-size:11px;line-height:16px;letter-spacing:.02em}
+
+/* Who the room sent a message to: one thin line in the space under the bubble,
+   opposite the timestamp, so it reads as a note about the message and never as
+   a second message. */
+.route-note{position:absolute;bottom:0;left:0;max-width:56%;overflow:hidden;color:var(--muted);font-size:11px;line-height:17px;opacity:.78;text-overflow:ellipsis;white-space:nowrap}
+.message.user .route-note{left:0;right:auto}
+.message.assistant .route-note{left:auto;right:28px;text-align:right}
+
+/* The `@` list sits where the slash list sits: only one of them is ever open. */
+.mention-suggestions button{align-items:center;gap:8px}
+.mention-suggestions strong{min-width:0}
+
+/* The host is a name in the top bar, not a page of settings. */
+.host-chip-wrap{position:relative;display:inline-flex;align-items:center}
+.host-chip{display:inline-flex;align-items:center;gap:5px;max-width:150px;padding:3px 9px;border:1px solid var(--border);border-radius:999px;background:transparent;color:var(--muted);font-size:11px;cursor:pointer}
+.host-chip:hover,.host-chip[aria-expanded="true"]{border-color:var(--accent);color:var(--ink)}
+.host-chip span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
+.host-menu{position:absolute;top:calc(100% + 8px);left:0;z-index:9;display:grid;gap:2px;min-width:190px;padding:8px;border:1px solid var(--border);border-radius:14px;background:var(--menu);box-shadow:0 14px 34px rgba(0,0,0,.35)}
+.host-menu button{display:flex;align-items:center;gap:8px;padding:7px 9px;border:0;border-radius:9px;background:transparent;color:var(--ink);font-size:13px;text-align:left;cursor:pointer}
+.host-menu button:hover,.host-menu button:focus-visible{background:rgba(255,255,255,.08);outline:0}
+.host-menu button span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
+.host-menu-label{padding:2px 9px 4px;color:var(--muted);font-size:11px}
+.host-flag{margin-left:auto;color:var(--accent);font-size:11px;font-weight:650}
diff --git a/apps/web/src/locales/en.ts b/apps/web/src/locales/en.ts
index 2988f6b..c954e13 100644
--- a/apps/web/src/locales/en.ts
+++ b/apps/web/src/locales/en.ts
@@ -56,7 +56,11 @@ export const en: { [K in keyof typeof zhTW]: string } = {
   chooseBot: "Choose a bot",
   startRoomDiscussion: "Start a discussion with {name}",
   startBotWork: "Start working with {name}",
-  roomWillReply: "{names} will all reply.",
+  roomWillReply: "{names} are here. Whoever is @-mentioned answers; otherwise the host, or the best fit, picks it up.",
+  everyoneMention: "everyone", mentionEveryoneHint: "every member answers", mentionList: "Members to mention",
+  routedTo: "{names} will answer this", handedTo: "→ handed to {name}",
+  today: "Today", yesterday: "Yesterday",
+  hostBadge: "Host", hostMenuLabel: "Who hosts", hostHint: "The host answers what nobody is named for. Tap to change it.",
   botWelcome: "Send a message and it will get it done on its own computer.",
   remembered: "Remembered",
   remember: "Remember",
@@ -292,6 +296,7 @@ export const en: { [K in keyof typeof zhTW]: string } = {
   privateComputerHint: "A fresh dedicated Docker desktop",
   create: "Create",
   groupDescription: "A group opens one chat where every selected agent speaks.",
+  groupHostHint: "{name} starts as host — one tap in the top bar swaps it.",
   groupName: "Group name",
   groupNamePlaceholder: "For example: product research",
   chooseBots: "Choose bots (at least two)",
@@ -340,7 +345,7 @@ export const en: { [K in keyof typeof zhTW]: string } = {
   helpBotsTitle: "Bots",
   helpBots: "Use + at the top left to add a bot. Click the list to chat. Right-click to pin, hide, or delete.",
   helpGroupsTitle: "Groups",
-  helpGroups: "+ → New group, pick at least two. One message, every agent in the group replies.",
+  helpGroups: "+ → New group, pick at least two. @ a name and that agent answers; unaddressed messages go to the host or the best fit.",
   helpComputerTitle: "Computer",
   helpComputer: "The Computer tab on the right is this agent’s desktop. Start it, take over mouse and keyboard, or let it drive.",
   helpMemoryTitle: "Memory",
diff --git a/apps/web/src/locales/zh-TW.ts b/apps/web/src/locales/zh-TW.ts
index 0ba970c..4d0df98 100644
--- a/apps/web/src/locales/zh-TW.ts
+++ b/apps/web/src/locales/zh-TW.ts
@@ -14,7 +14,11 @@ export const zhTW = {
   unreadMessages: "{count} 則未讀訊息", members: "{count} 位成員", hideHiddenItems: "隱藏已隱藏項目", showHiddenItems: "顯示已隱藏項目",
   mcpConnected: "{count} 個 MCP 已連線", connectMcpServer: "接入 MCP server",
   openOnPhone: "在手機開啟", settings: "設定", about: "關於", helpCenter: "說明中心", sendFeedback: "傳送意見回饋", logout: "登出", workspaceMenu: "工作區選單",
-  chooseBot: "選擇一個機器人", startRoomDiscussion: "和 {name} 開始討論", startBotWork: "和 {name} 開始工作", roomWillReply: "{names} 會一起回覆。",
+  chooseBot: "選擇一個機器人", startRoomDiscussion: "和 {name} 開始討論", startBotWork: "和 {name} 開始工作", roomWillReply: "{names} 都在這裡。@誰就由誰回覆，沒點名時由主持人或最合適的 Agent 接手。",
+  everyoneMention: "所有人", mentionEveryoneHint: "每個人都回覆", mentionList: "可點名的成員",
+  routedTo: "本輪由 {names} 回覆", handedTo: "→ 交給 {name}",
+  today: "今天", yesterday: "昨天",
+  hostBadge: "主持人", hostMenuLabel: "由誰主持", hostHint: "沒被點名的時候由主持人回答。點一下換人。",
   botWelcome: "傳送訊息，讓它在自己的電腦上完成任務。", remembered: "已記住", remember: "記住", working: "{name} 正在工作…",
   copyCode: "複製程式碼", copiedCode: "已複製", copyMessage: "複製", copiedMessage: "已複製",
   anotherConversationQueued: "另一則對話正在執行，這則會排隊。",
@@ -93,7 +97,7 @@ export const zhTW = {
   hudBooting: "電腦啟動中…", hudWaking: "喚醒中…", hudConnecting: "連線中…", hudHandoff: "換手中…",
   pasteToRemoteComputer: "貼到遠端電腦", pasteRemoteHelp: "把外面的文字貼在這裡，再送進 VNC。這個方式在區網 HTTP 也能使用。", pasteTextPlaceholder: "在此貼上文字…", pasteIntoVnc: "貼入 VNC",
   botNamePlaceholder: "例如：研究助理", sharedComputerHint: "與其他機器人共用環境", privateComputerHint: "全新的獨立 Docker", create: "建立",
-  groupDescription: "拉進群組會開一個對話，選中的 Agent 都會在裡面發言。", groupName: "群組名稱", groupNamePlaceholder: "例如：產品研究", chooseBots: "選擇機器人（至少兩位）", creating: "建立中…", createGroup: "建立群組",
+  groupDescription: "拉進群組會開一個對話，選中的 Agent 都會在裡面發言。", groupHostHint: "第一位（{name}）先擔任主持人，以後在上方一點就能換。", groupName: "群組名稱", groupNamePlaceholder: "例如：產品研究", chooseBots: "選擇機器人（至少兩位）", creating: "建立中…", createGroup: "建立群組",
   deleteGroup: "刪除群組", deleteNamed: "刪除 {name}？", deleteGroupDescription: "群組對話會刪除。裡面的機器人與他們自己的對話、記憶都會保留。", deleteDedicatedBotDescription: "對話、私人電腦與其中的檔案都會永久刪除。", deleteSharedBotDescription: "對話會刪除，但共用電腦與其中的檔案會保留。",
   phoneAccessDescription: "同一區網的手機用瀏覽器打開這個網址，再用同一個存取 token 登入。", localAddressWarning: "這是本機位址，手機打不開。請改成這台電腦的區網 IP，例如 http://192.168.x.x:3101。",
   close: "關閉", copied: "已複製", copyUrl: "複製網址", workspaceName: "工作區名稱", showHiddenBots: "顯示已隱藏的機器人", collapseRightSidebar: "收合右側欄",
@@ -113,7 +117,7 @@ export const zhTW = {
   workspaceModelHint: "先選供應商，再填金鑰與模型。OpenAI 相容需要自己填端點。",
   aboutDescription: "本機多 Agent 工作區。每個機器人有自己的 Linux 電腦，也可以拉進群組一起討論，並接入 MCP 工具。",
   apiStatus: "API 狀態：{status}", statusNormal: "正常", statusUnavailable: "無法連線", statusChecking: "檢查中…",
-  helpBotsTitle: "機器人", helpBots: "左上角 ＋ 新增機器人。點左側列進入對話。右鍵可以釘選、隱藏或刪除。", helpGroupsTitle: "群組", helpGroups: "＋ → 新增群組，選至少兩位。傳一句話，裡面的 Agent 都會回。",
+  helpBotsTitle: "機器人", helpBots: "左上角 ＋ 新增機器人。點左側列進入對話。右鍵可以釘選、隱藏或刪除。", helpGroupsTitle: "群組", helpGroups: "＋ → 新增群組，選至少兩位。@誰就由誰回；沒點名時，主持人或最合適的 Agent 會接手。",
   helpComputerTitle: "電腦", helpComputer: "右側「電腦」是這個 Agent 的獨立桌面。可以啟動、接管滑鼠鍵盤，或讓它自己操作。", helpMemoryTitle: "記憶", helpMemory: "清除對話不會刪長期記憶。可以叫 Agent 記住，或在右側「記憶」手動新增。",
   helpMcpTitle: "MCP 外掛", helpMcp: "左下「外掛程式」接入 MCP server。連上的工具會顯示在畫面上，對話時 Agent 可以使用。",
   helpSkillsTitle: "技能", helpSkills: "＋ → 教它一項任務，示範一次就會整理成技能。示範結束後可以匯出 JSON，或把別人的技能檔匯入，換一個機器人也適用。",
diff --git a/apps/web/src/mentions.ts b/apps/web/src/mentions.ts
new file mode 100644
index 0000000..6e3dc16
--- /dev/null
+++ b/apps/web/src/mentions.ts
@@ -0,0 +1,56 @@
+import type { RoomMember } from "./types";
+
+/** One row of the `@` list. A null `member` is the whole-room escape hatch. */
+export interface MentionChoice {
+  name: string;
+  member: RoomMember | null;
+}
+
+/**
+ * The `@`-token under the caret, or null when the caret is not writing one.
+ * A token ends at a space, so `@小美 幫我看` stops offering the list the moment
+ * the name is finished, and `mail@example.com` never opens it.
+ */
+export function mentionToken(text: string, caret: number): string | null {
+  const end = Math.max(0, Math.min(caret, text.length));
+  const hit = /(?:^|\s)@([^\s@]*)$/.exec(text.slice(0, end));
+  return hit ? hit[1] : null;
+}
+
+/**
+ * Who the token could mean, in room order, capped so the list stays one glance.
+ * `everyone` — the one name that reaches the whole room — leads the list while
+ * the token is empty or could still become it, because typing `@` is where a
+ * person discovers that escape hatch.
+ */
+export function mentionChoices(
+  token: string,
+  members: RoomMember[],
+  everyone: string,
+): MentionChoice[] {
+  const needle = token.trim().toLowerCase();
+  const choices: MentionChoice[] = [];
+  if (everyone.toLowerCase().startsWith(needle)) {
+    choices.push({ name: everyone, member: null });
+  }
+  for (const member of members) {
+    if (member.name.toLowerCase().includes(needle)) choices.push({ name: member.name, member });
+  }
+  return choices.slice(0, 6);
+}
+
+/**
+ * Replace the token being typed with a chosen name and one space, leaving the
+ * rest of the message where it was. The new caret sits after that space, so the
+ * next keystroke continues the sentence instead of reopening the list.
+ */
+export function acceptMention(
+  text: string,
+  caret: number,
+  name: string,
+): { text: string; caret: number } {
+  const end = Math.max(0, Math.min(caret, text.length));
+  const head = text.slice(0, end).replace(/@([^\s@]*)$/, "");
+  const inserted = `${head}@${name} `;
+  return { text: inserted + text.slice(end), caret: inserted.length };
+}
diff --git a/apps/web/src/refinements.css b/apps/web/src/refinements.css
index 1d92596..c8bad2e 100644
--- a/apps/web/src/refinements.css
+++ b/apps/web/src/refinements.css
@@ -620,6 +620,8 @@
 
 
 .dialog-lead{margin:0;color:var(--muted);line-height:1.5;font-size:13px}
+/* One quiet sentence under a form: what will happen by default, so the human has nothing to configure. */
+.dialog-note{margin:-4px 0 0;color:var(--muted);font-size:12px;line-height:1.5}
 
 
 @keyframes computer-hud-bob{0%,100%{transform:translateY(0) rotate(-4deg)}50%{transform:translateY(-3px) rotate(5deg)}}
diff --git a/apps/web/src/responsive.css b/apps/web/src/responsive.css
index dddc302..fcf6e88 100644
--- a/apps/web/src/responsive.css
+++ b/apps/web/src/responsive.css
@@ -2,7 +2,7 @@
 @media(max-width:700px){.app-shell{display:block}.sidebar{position:fixed;z-index:40;inset:0 auto 0 0;width:min(300px,88vw);transform:translateX(-105%);transition:.2s;box-shadow:20px 0 60px #000}.sidebar.open{transform:none}.chat-panel{height:100%}.mobile-menu{display:inline-flex}.topbar{padding:0 12px}.messages{padding:24px 18px 16px}.composer{left:12px;right:12px}.computer-overlay>header{height:auto;min-height:64px;flex-wrap:wrap;padding:10px}.computer-overlay>header>div:last-child{flex-wrap:wrap;justify-content:flex-end}.overlay-screen{padding:8px}.mode-grid{grid-template-columns:1fr}}
 @media(max-width:1200px){.app-shell{grid-template-columns:230px minmax(0,1fr) 330px}}
 @media(max-width:1050px){.app-shell{grid-template-columns:250px minmax(0,1fr)}}
-@media(max-width:700px){.chat-panel{--chat-gutter:18px}.app-shell{display:block}.message{width:100%}.message>span,.message>.message-body,.message-stack{max-width:90%}.composer-dock{padding:20px var(--chat-gutter) 16px}.composer{width:var(--chat-col);min-height:60px}.composer-files{padding:2px 4px 8px 8px}.file-card{max-width:100%;height:52px}.file-card-remove{flex-basis:32px;width:32px;height:32px}.message.with-files .msg-attachments{max-width:100%}.messages{padding-bottom:16px}}
+@media(max-width:700px){.chat-panel{--chat-gutter:18px}.app-shell{display:block}.message{width:100%}.day-divider{width:100%}.message>span,.message>.message-body,.message-stack{max-width:90%}.composer-dock{padding:20px var(--chat-gutter) 16px}.composer{width:var(--chat-col);min-height:60px}.composer-files{padding:2px 4px 8px 8px}.file-card{max-width:100%;height:52px}.file-card-remove{flex-basis:32px;width:32px;height:32px}.message.with-files .msg-attachments{max-width:100%}.messages{padding-bottom:16px}}
 @media(prefers-reduced-motion:reduce){.avatar.blobatar.thinking:before,.avatar.blobatar.thinking:after,.thinking-dots i{animation:none!important}}
 @media(max-width:1200px){.app-shell.right-open{grid-template-columns:230px minmax(0,1fr) 340px}.app-shell.right-collapsed{grid-template-columns:230px minmax(0,1fr) 52px}}
 @media(max-width:1050px){
diff --git a/apps/web/src/types.ts b/apps/web/src/types.ts
index f9db9aa..dfef92d 100644
--- a/apps/web/src/types.ts
+++ b/apps/web/src/types.ts
@@ -5,10 +5,10 @@ export type BlobatarShape = "round"|"organic"|"boxy"|"capsule"|"nub"|"cloud"|"dr
 export type AvatarShape = BlobatarShape|"blob"|"squircle"|"diamond"|"drop"|"organic-4"|"organic-5"|"organic-6"|"organic-7"|"organic-8"|"organic-9"|"organic-10"|"organic-11"|"cat"|"bunny"|"star"|"heart"|"egg"|"ghost"|"sprout"|"cactus"|"mushroom"|"paw";
 export interface Bot { id:string; spaceId:string; name:string; title:string; description:string; avatarColor:string; avatarShape:AvatarShape; tags:string[]; pinned:boolean; hidden:boolean; groupName:string|null; unreadCount:number; lastMessageAt:string|null; instructions:string; threadId:string; computerId:string; computerMode:ComputerMode; memoryEnabled:boolean }
 export interface Session { id:string; botId:string; title:string; status:"active"|"archived"; createdAt:string; updatedAt:string; nextMessageSeq:number; historySummary:string; historySummarySeq:number }
-export interface Message { id:string; sessionId?:string; seq?:number; role:string; body:string; blocks?:unknown[]; runId?:string|null; clientNonce?:string|null; createdAt:string; speakerBotId?:string|null; speakerName?:string|null; speakerColor?:string|null; speakerShape?:AvatarShape|null }
+export interface Message { id:string; sessionId?:string; seq?:number; role:string; body:string; blocks?:unknown[]; runId?:string|null; clientNonce?:string|null; createdAt:string; speakerBotId?:string|null; speakerName?:string|null; speakerColor?:string|null; speakerShape?:AvatarShape|null; replyBots?:RoomMember[] }
 export interface MessageFile { kind:"image"|"file"; name:string; mimeType?:string; size?:number }
 export interface RoomMember { id:string; name:string; avatarColor:string; avatarShape:AvatarShape }
-export interface Room { id:string; name:string; members:RoomMember[]; lastMessageAt:string|null; lastPreview:string|null; unreadCount:number }
+export interface Room { id:string; name:string; members:RoomMember[]; hostBotId?:string|null; lastMessageAt:string|null; lastPreview:string|null; unreadCount:number }
 export interface ComputerStatus { botId:string; mode:ComputerMode; state:ComputerState; sharedInput?:boolean; controlHolder:"none"|"bot"|"user"; takeoverRequested:boolean; busyBotName:string|null; busySessionId:string|null; busyRunId:string|null; busyStep?:string|null; usingComputer?:boolean; waitingRunId?:string|null; waitingSessionId?:string|null; queuedRuns?:number; display:string|null; profileMode:string; screenAvailable:boolean }
 /** One line of the live trail a run writes while it works. */
 export type RunActivityKind = "run"|"model"|"tool"|"retry"|"notice"|"memory";
diff --git a/crates/api/src/main.rs b/crates/api/src/main.rs
index 208de0e..a1b6da3 100644
--- a/crates/api/src/main.rs
+++ b/crates/api/src/main.rs
@@ -10,6 +10,7 @@ mod monitor;
 mod retention;
 mod rooms;
 mod routes;
+mod routing;
 mod runs;
 mod schedules;
 mod screen_proxy;
diff --git a/crates/api/src/memory.rs b/crates/api/src/memory.rs
index 2e6a733..3b42f34 100644
--- a/crates/api/src/memory.rs
+++ b/crates/api/src/memory.rs
@@ -1280,4 +1280,91 @@ mod tests {
                 .id
         );
     }
+
+    /// A conversation that holds remembered lines can still be removed: the
+    /// memory survives, pointing at nothing, and the guard keeps rejecting a
+    /// genuine move into another agent's conversation.
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn deleting_a_conversation_keeps_its_memories_and_the_guard(pool: sqlx::PgPool) {
+        sqlx::query("INSERT INTO users(id,name) VALUES ('u','test')")
+            .execute(&pool)
+            .await
+            .unwrap();
+        sqlx::query("INSERT INTO spaces(id,user_id,name) VALUES ('s','u','test')")
+            .execute(&pool)
+            .await
+            .unwrap();
+        for bot in ["a", "b"] {
+            sqlx::query("INSERT INTO bots(id,space_id,user_id,name) VALUES ($1,'s','u',$1)")
+                .bind(bot)
+                .execute(&pool)
+                .await
+                .unwrap();
+            sqlx::query("INSERT INTO threads(id,space_id,user_id,bot_id) VALUES ($1,'s','u',$2)")
+                .bind(format!("thread-{bot}"))
+                .bind(bot)
+                .execute(&pool)
+                .await
+                .unwrap();
+        }
+        sqlx::query(
+            "INSERT INTO runs(id,space_id,user_id,bot_id,thread_id,status,prompt)
+             VALUES ('run-a','s','u','a','thread-a','completed','hi')",
+        )
+        .execute(&pool)
+        .await
+        .unwrap();
+        sqlx::query(
+            "INSERT INTO messages(id,thread_id,seq,role,body,run_id)
+             VALUES ('msg-a','thread-a',1,'user','remember this','run-a')",
+        )
+        .execute(&pool)
+        .await
+        .unwrap();
+        // One saved from the chat (message + session), one by the remember tool
+        // (run + session): both link into the conversation being removed.
+        let from_chat = Uuid::new_v4();
+        let from_tool = Uuid::new_v4();
+        sqlx::query(
+            "INSERT INTO memory_items(id,space_id,user_id,bot_id,session_id,source_run_id,source_message_id,content)
+             VALUES ($1,'s','u','a','thread-a',NULL,'msg-a','saved from chat'),
+                    ($2,'s','u','a','thread-a','run-a',NULL,'saved by tool')",
+        )
+        .bind(from_chat)
+        .bind(from_tool)
+        .execute(&pool)
+        .await
+        .unwrap();
+
+        sqlx::query("DELETE FROM threads WHERE id='thread-a'")
+            .execute(&pool)
+            .await
+            .expect("a conversation with remembered lines can be deleted");
+        let left: Vec<(Option<String>, Option<String>, Option<String>)> = sqlx::query_as(
+            "SELECT session_id, source_run_id, source_message_id FROM memory_items
+             WHERE bot_id='a' ORDER BY content",
+        )
+        .fetch_all(&pool)
+        .await
+        .unwrap();
+        assert_eq!(left, vec![(None, None, None), (None, None, None)]);
+
+        // The guard still holds: memory cannot be pointed at another agent's
+        // conversation after the fact.
+        let moved = sqlx::query("UPDATE memory_items SET session_id='thread-b' WHERE id=$1")
+            .bind(from_chat)
+            .execute(&pool)
+            .await;
+        assert!(
+            moved.is_err(),
+            "re-homing into another agent's thread must fail"
+        );
+        let kept: i64 = sqlx::query_scalar(
+            "SELECT count(*) FROM memory_items WHERE bot_id='a' AND session_id IS NULL",
+        )
+        .fetch_one(&pool)
+        .await
+        .unwrap();
+        assert_eq!(kept, 2);
+    }
 }
diff --git a/crates/api/src/rooms.rs b/crates/api/src/rooms.rs
index 149f99a..42e3586 100644
--- a/crates/api/src/rooms.rs
+++ b/crates/api/src/rooms.rs
@@ -5,7 +5,7 @@ use axum::http::StatusCode;
 use axum::routing::get;
 use axum::{Json, Router};
 use lazyboy_contracts::{
-    CreateRoomInput, CreateSessionInput, Room, RoomMember, RoomStatus, Session,
+    CreateRoomInput, CreateSessionInput, Room, RoomMember, RoomStatus, Session, UpdateRoomInput,
 };
 use serde_json::{Value, json};
 use uuid::Uuid;
@@ -19,7 +19,10 @@ type ApiError = (StatusCode, Json<Value>);
 pub fn router() -> Router<AppState> {
     Router::new()
         .route("/api/rooms", get(list_rooms).post(create_room))
-        .route("/api/rooms/{id}", get(get_room).delete(delete_room))
+        .route(
+            "/api/rooms/{id}",
+            get(get_room).patch(update_room).delete(delete_room),
+        )
         .route(
             "/api/rooms/{id}/sessions",
             get(list_sessions).post(create_session),
@@ -64,10 +67,12 @@ async fn members_for(state: &AppState, room_id: &str) -> Result<Vec<RoomMember>,
     Ok(rows.into_iter().map(member_from_row).collect())
 }
 
-/// `room_from_id` projection: id, name, last message time, preview, unread count.
+/// `room_from_id` projection: id, name, host, last message time, preview, unread
+/// count.
 type RoomSummaryRow = (
     String,
     String,
+    Option<String>,
     Option<chrono::DateTime<chrono::Utc>>,
     Option<String>,
     i64,
@@ -79,7 +84,7 @@ async fn room_from_id(
     id: &str,
 ) -> Result<Option<Room>, sqlx::Error> {
     let row: Option<RoomSummaryRow> = sqlx::query_as(
-            "SELECT r.id, r.name,
+            "SELECT r.id, r.name, r.host_bot_id,
                     (SELECT MAX(m.created_at) FROM messages m JOIN threads t ON t.id=m.thread_id WHERE t.room_id=r.id),
                     (SELECT m.body FROM messages m JOIN threads t ON t.id=m.thread_id
                      WHERE t.room_id=r.id ORDER BY m.created_at DESC, m.seq DESC LIMIT 1),
@@ -96,13 +101,14 @@ async fn room_from_id(
         .bind(&actor.user_id)
         .fetch_optional(state.pool())
         .await?;
-    let Some((id, name, last_message_at, last_preview, unread_count)) = row else {
+    let Some((id, name, host_bot_id, last_message_at, last_preview, unread_count)) = row else {
         return Ok(None);
     };
     Ok(Some(Room {
         members: members_for(state, &id).await?,
         id,
         name,
+        host_bot_id,
         last_message_at,
         last_preview,
         unread_count,
@@ -149,6 +155,15 @@ async fn create_room(
             Json(json!({"message":"群組需要名稱，並至少兩位機器人"})),
         ));
     }
+    let host_bot_id = input.host_bot_id;
+    if let Some(host) = host_bot_id.as_deref()
+        && !member_ids.iter().any(|member| member.as_str() == host)
+    {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            Json(json!({"message":"主持人必須是群組成員"})),
+        ));
+    }
     let mut members = Vec::new();
     for bot_id in &member_ids {
         let exists: Option<(String, String, String, String)> = sqlx::query_as(
@@ -170,17 +185,20 @@ async fn create_room(
         members.push(member_from_row(row));
     }
     let room_id = Uuid::new_v4().to_string();
-    let host_id = members[0].id.clone();
+    // The host is decided once, here: the member the human chose, or simply the
+    // first one. Starting a group needs no other setting.
+    let host_id = host_bot_id.unwrap_or_else(|| members[0].id.clone());
     let mut tx = state
         .pool()
         .begin()
         .await
         .map_err(|error| internal(error.to_string()))?;
-    sqlx::query("INSERT INTO rooms (id,space_id,user_id,name) VALUES ($1,$2,$3,$4)")
+    sqlx::query("INSERT INTO rooms (id,space_id,user_id,name,host_bot_id) VALUES ($1,$2,$3,$4,$5)")
         .bind(&room_id)
         .bind(&actor.space_id)
         .bind(&actor.user_id)
         .bind(name)
+        .bind(&host_id)
         .execute(&mut *tx)
         .await
         .map_err(|error| internal(error.to_string()))?;
@@ -213,6 +231,7 @@ async fn create_room(
             id: room_id,
             name: name.into(),
             members,
+            host_bot_id: Some(host_id),
             last_message_at: None,
             last_preview: None,
             unread_count: 0,
@@ -258,6 +277,59 @@ async fn delete_room(
     Ok(StatusCode::NO_CONTENT)
 }
 
+/// Change who leads the room. This is the only room setting that exists, and it
+/// is reached by one tap on a member — there is no settings page to open.
+async fn update_room(
+    State(state): State<AppState>,
+    Path(id): Path<String>,
+    Json(input): Json<UpdateRoomInput>,
+) -> Result<Json<Room>, ApiError> {
+    let actor = actor(&state).await?;
+    let current = room_from_id(&state, &actor, &id)
+        .await
+        .map_err(|error| internal(error.to_string()))?
+        .ok_or_else(|| {
+            (
+                StatusCode::NOT_FOUND,
+                Json(json!({"message":"group not found"})),
+            )
+        })?;
+    let Some(host_bot_id) = input.host_bot_id else {
+        return Ok(Json(current));
+    };
+    if !current
+        .members
+        .iter()
+        .any(|member| member.id == host_bot_id)
+    {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            Json(json!({"message":"主持人必須是群組成員"})),
+        ));
+    }
+    let updated = sqlx::query(
+        "UPDATE rooms SET host_bot_id=$2, updated_at=now()
+         WHERE id=$1 AND space_id=$3 AND user_id=$4",
+    )
+    .bind(&id)
+    .bind(&host_bot_id)
+    .bind(&actor.space_id)
+    .bind(&actor.user_id)
+    .execute(state.pool())
+    .await
+    .map_err(|error| internal(error.to_string()))?;
+    if updated.rows_affected() == 0 {
+        return Err((
+            StatusCode::NOT_FOUND,
+            Json(json!({"message":"group not found"})),
+        ));
+    }
+    room_from_id(&state, &actor, &id)
+        .await
+        .map(|room| Json(room.unwrap_or(current)))
+        .map_err(|error| internal(error.to_string()))
+}
+
 async fn list_sessions(
     State(state): State<AppState>,
     Path(id): Path<String>,
diff --git a/crates/api/src/routing.rs b/crates/api/src/routing.rs
new file mode 100644
index 0000000..c4be915
--- /dev/null
+++ b/crates/api/src/routing.rs
@@ -0,0 +1,1047 @@
+//! Who is allowed to answer a group message.
+//!
+//! A room used to wake every member for every message, so a group of four paid
+//! for four model calls (and four desktop claims) to get one useful answer. The
+//! audience is now decided once, when the message arrives: an `@name` is law,
+//! and without one a single short model call picks the members whose role fits
+//! the ask. When nothing fits, the host answers — a message is never left with
+//! nobody to read it, because a silently dropped message is worse than one
+//! wasted reply.
+
+use std::time::Duration;
+
+use lazyboy_contracts::ModelProvider;
+use lazyboy_harness::{
+    CredentialChain, DynModel, ResolveModelRequest, connect_model, credential_from_env,
+    resolve_backend,
+};
+use rig_core::completion::message::{AssistantContent, Message, UserContent};
+
+use crate::db::Actor;
+use crate::state::AppState;
+
+/// The picker is a nicety, not a gate: past this the host takes over, so a slow
+/// helper never holds up a chat message.
+const ROUTER_TIMEOUT: Duration = Duration::from_millis(1200);
+/// How many members one unprefixed message may wake.
+const ROUTER_CAP: usize = 3;
+/// Recent lines and role text handed to the picker.
+const ROUTER_HISTORY: i64 = 6;
+const FIELD_CHARS: usize = 100;
+const LINE_CHARS: usize = 200;
+/// `@所有人` and its spellings: everybody, and no model call at all. The web
+/// composer offers the escape hatch in whatever language the screen is in, so
+/// every spelling it can insert has to be understood here too.
+const ALL_KEYWORDS: [&str; 5] = ["所有人", "全部", "all", "everyone", "everybody"];
+
+const PICKER_SYSTEM: &str = "You decide which members of a group chat should answer the newest message.
+
+Reply with names from the roster only, separated by 、, at most three of them. Choose a member when the message falls inside what that member does. Reply NONE when no roster member fits, and add nothing else.
+Never invent a name, never explain your choice, and never answer the message yourself.";
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Member {
+    pub id: String,
+    pub name: String,
+    /// What this member says it does (title + description). Picker input only;
+    /// empty is fine.
+    pub role: String,
+}
+
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub struct Mentions {
+    /// `@所有人` appeared.
+    pub all: bool,
+    /// Member ids in the order they were named.
+    pub ids: Vec<String>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Reason {
+    All,
+    Mention,
+    Routed,
+    Host,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Audience {
+    pub targets: Vec<String>,
+    pub reason: Reason,
+}
+
+/// A room reduced to what routing needs: who leads it and who is in it.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Room {
+    pub id: String,
+    pub host_id: String,
+    pub members: Vec<Member>,
+}
+
+/// Names written as `@名字`, longest name first so a short member cannot steal a
+/// longer member's mention.
+pub fn parse_mentions(text: &str, members: &[Member]) -> Mentions {
+    let mut mentions = Mentions::default();
+    let chars: Vec<char> = text.chars().collect();
+    for (position, ch) in chars.iter().enumerate() {
+        // `mail@example.com` is not a mention: `@` has to open a word.
+        if *ch != '@' || (position > 0 && chars[position - 1].is_alphanumeric()) {
+            continue;
+        }
+        let tail: String = chars[position + 1..].iter().collect();
+        if ALL_KEYWORDS.iter().any(|word| name_hit(&tail, word)) {
+            mentions.all = true;
+            continue;
+        }
+        if let Some(id) = find_names(&tail, members, true).into_iter().next()
+            && !mentions.ids.contains(&id)
+        {
+            mentions.ids.push(id);
+        }
+    }
+    mentions
+}
+
+/// Names of roster members that appear in `text`, in order of appearance.
+/// `anchored` accepts a name only at the very start of `text`, which is what a
+/// mention needs after the `@`.
+fn find_names(text: &str, members: &[Member], anchored: bool) -> Vec<String> {
+    let mut ranked: Vec<&Member> = members
+        .iter()
+        .filter(|member| !member.name.trim().is_empty())
+        .collect();
+    ranked.sort_by_key(|member| std::cmp::Reverse(member.name.chars().count()));
+    let chars: Vec<char> = text.chars().collect();
+    let mut ids: Vec<String> = Vec::new();
+    let mut position = 0usize;
+    while position < chars.len() {
+        let tail: String = chars[position..].iter().collect();
+        if let Some(member) = ranked.iter().find(|member| name_hit(&tail, &member.name))
+            && !ids.contains(&member.id)
+        {
+            ids.push(member.id.clone());
+        }
+        if anchored {
+            break;
+        }
+        position += 1;
+    }
+    ids
+}
+
+/// Does `tail` open with `name`? ASCII names need a word boundary after them so
+/// `@Ali` cannot pick "Alice"; CJK names run together, so the longest match is
+/// already the boundary.
+fn name_hit(tail: &str, name: &str) -> bool {
+    let lowered = tail.to_lowercase();
+    let needle = name.trim().to_lowercase();
+    if needle.is_empty() || !lowered.starts_with(&needle) {
+        return false;
+    }
+    if !needle
+        .chars()
+        .next_back()
+        .is_some_and(|last| last.is_ascii_alphanumeric())
+    {
+        return true;
+    }
+    match lowered.chars().nth(needle.chars().count()) {
+        None => true,
+        Some(next) => !(next.is_ascii_alphanumeric() || next == '-' || next == '_'),
+    }
+}
+
+/// The picker's answer reduced to roster ids. It may write "阿明、小美", a JSON
+/// array, or prose naming people; anything outside the roster is dropped.
+pub fn parse_router_reply(raw: &str, members: &[Member]) -> Vec<String> {
+    let mut picked = find_names(raw, members, false);
+    picked.truncate(ROUTER_CAP);
+    picked
+}
+
+/// Who should run for one message: a name is law, `@所有人` is everybody, and
+/// only an unaddressed message consults the picker.
+pub fn resolve_audience(
+    members: &[Member],
+    mentions: &Mentions,
+    host_id: &str,
+    busy: &[String],
+    routed: &[String],
+) -> Audience {
+    let roster: Vec<&String> = members.iter().map(|member| &member.id).collect();
+    if mentions.all {
+        return Audience {
+            targets: roster.into_iter().cloned().collect(),
+            reason: Reason::All,
+        };
+    }
+    let named: Vec<String> = mentions
+        .ids
+        .iter()
+        .filter(|id| roster.contains(id))
+        .cloned()
+        .collect();
+    if !named.is_empty() {
+        return Audience {
+            targets: named,
+            reason: Reason::Mention,
+        };
+    }
+    let chosen: Vec<String> = routed
+        .iter()
+        .filter(|id| roster.contains(id) && !busy.contains(id))
+        .cloned()
+        .collect();
+    if !chosen.is_empty() {
+        return Audience {
+            targets: chosen,
+            reason: Reason::Routed,
+        };
+    }
+    // Never zero: the host picks up what nobody was chosen for.
+    Audience {
+        targets: vec![host_id.to_string()],
+        reason: Reason::Host,
+    }
+}
+
+/// The room a thread belongs to, or `None` for a one-to-one conversation.
+pub(crate) async fn room_for_thread(
+    state: &AppState,
+    thread_id: &str,
+) -> Result<Option<Room>, String> {
+    // The column is nullable and the row may be missing: both read as "not a
+    // room", so the outer `Option` (no row) and the inner one (NULL) are
+    // flattened together. Decoding the column straight into `String` made every
+    // one-to-one message fail with an "unexpected null".
+    let room_id: Option<Option<String>> =
+        sqlx::query_scalar("SELECT room_id FROM threads WHERE id=$1")
+            .bind(thread_id)
+            .fetch_optional(state.pool())
+            .await
+            .map_err(|error| error.to_string())?;
+    let Some(room_id) = room_id.flatten() else {
+        return Ok(None);
+    };
+    let rows: Vec<(String, String, String, String)> = sqlx::query_as(
+        "SELECT b.id, b.name, b.title, b.description
+         FROM room_members m JOIN bots b ON b.id=m.bot_id
+         WHERE m.room_id=$1
+         ORDER BY m.created_at, b.name",
+    )
+    .bind(&room_id)
+    .fetch_all(state.pool())
+    .await
+    .map_err(|error| error.to_string())?;
+    if rows.is_empty() {
+        return Ok(None);
+    }
+    let members: Vec<Member> = rows
+        .into_iter()
+        .map(|(id, name, title, description)| Member {
+            role: format!("{title} {description}").trim().to_string(),
+            id,
+            name,
+        })
+        .collect();
+    let host: Option<Option<String>> =
+        sqlx::query_scalar("SELECT host_bot_id FROM rooms WHERE id=$1")
+            .bind(&room_id)
+            .fetch_optional(state.pool())
+            .await
+            .map_err(|error| error.to_string())?;
+    // A deleted host, or a room written before this column existed, falls back
+    // to the first member — who is the one that used to answer anyway.
+    let host_id = host
+        .flatten()
+        .filter(|host| members.iter().any(|member| member.id == *host))
+        .unwrap_or_else(|| members[0].id.clone());
+    Ok(Some(Room {
+        id: room_id,
+        host_id,
+        members,
+    }))
+}
+
+/// Members of `room` that already have a run of their own in flight.
+pub(crate) async fn busy_members(state: &AppState, room: &Room) -> Result<Vec<String>, String> {
+    let roster: Vec<String> = room
+        .members
+        .iter()
+        .map(|member| member.id.clone())
+        .collect();
+    let busy: Vec<String> = sqlx::query_scalar(
+        "SELECT DISTINCT bot_id FROM runs
+         WHERE bot_id = ANY($1)
+           AND status IN ('queued','leased','running','waiting_input','waiting_takeover')",
+    )
+    .bind(&roster)
+    .fetch_all(state.pool())
+    .await
+    .map_err(|error| error.to_string())?;
+    Ok(busy)
+}
+
+/// Decide the audience for a message that has not been written yet. The model
+/// call happens outside the message transaction, so a slow picker never holds a
+/// row lock, and every failure path lands on the host.
+pub(crate) async fn audience_for(
+    state: &AppState,
+    actor: &Actor,
+    room: &Room,
+    thread_id: &str,
+    text: &str,
+) -> Audience {
+    let mentions = parse_mentions(text, &room.members);
+    let decided = resolve_audience(&room.members, &mentions, &room.host_id, &[], &[]);
+    if decided.reason != Reason::Host {
+        log(room, thread_id, &decided);
+        return decided;
+    }
+    let busy = busy_members(state, room).await.unwrap_or_default();
+    // Two members need no referee: the host answers, and naming the other one
+    // is free.
+    let routed = if room.members.len() > 2 {
+        pick(state, actor, room, thread_id, text).await
+    } else {
+        Vec::new()
+    };
+    let decided = resolve_audience(&room.members, &mentions, &room.host_id, &busy, &routed);
+    log(room, thread_id, &decided);
+    decided
+}
+
+fn log(room: &Room, thread_id: &str, audience: &Audience) {
+    tracing::info!(
+        room = room.id,
+        thread = thread_id,
+        reason = reason_label(audience.reason),
+        targets = ?audience.targets,
+        "room routing"
+    );
+}
+
+pub fn reason_label(reason: Reason) -> &'static str {
+    match reason {
+        Reason::All => "all",
+        Reason::Mention => "mention",
+        Reason::Routed => "routed",
+        Reason::Host => "host",
+    }
+}
+
+/// One short model call: which names fit this message?
+async fn pick(
+    state: &AppState,
+    actor: &Actor,
+    room: &Room,
+    thread_id: &str,
+    text: &str,
+) -> Vec<String> {
+    let model = match router_model(state, actor).await {
+        Ok(model) => model,
+        Err(error) => {
+            tracing::warn!("room router unavailable: {error}");
+            return Vec::new();
+        }
+    };
+    let prompt = match prompt_for(state, room, thread_id, text).await {
+        Ok(prompt) => prompt,
+        Err(error) => {
+            tracing::warn!("room router prompt: {error}");
+            return Vec::new();
+        }
+    };
+    let attempt = tokio::time::timeout(
+        ROUTER_TIMEOUT,
+        crate::runs::complete_once(
+            &model,
+            Message::User {
+                content: vec![UserContent::text(prompt)],
+            },
+            PICKER_SYSTEM,
+            &[],
+            &[],
+        ),
+    )
+    .await;
+    let raw = match attempt {
+        Ok(Ok(parts)) => parts
+            .into_iter()
+            .filter_map(|part| match part {
+                AssistantContent::Text(text) => Some(text.text),
+                _ => None,
+            })
+            .collect::<Vec<_>>()
+            .join(" "),
+        Ok(Err(error)) => {
+            tracing::warn!("room router call: {error}");
+            return Vec::new();
+        }
+        Err(_) => {
+            tracing::warn!("room router timed out; the host answers");
+            return Vec::new();
+        }
+    };
+    parse_router_reply(&raw, &room.members)
+}
+
+async fn prompt_for(
+    state: &AppState,
+    room: &Room,
+    thread_id: &str,
+    text: &str,
+) -> Result<String, String> {
+    let recent: Vec<(String, String)> = sqlx::query_as(
+        "SELECT COALESCE(b.name, '你') AS speaker, m.body
+         FROM messages m LEFT JOIN bots b ON b.id=m.speaker_bot_id
+         WHERE m.thread_id=$1
+         ORDER BY m.seq DESC LIMIT $2",
+    )
+    .bind(thread_id)
+    .bind(ROUTER_HISTORY)
+    .fetch_all(state.pool())
+    .await
+    .map_err(|error| error.to_string())?;
+    let mut prompt = String::from("Roster (name — what they do):\n");
+    for member in &room.members {
+        prompt.push_str(&format!(
+            "- {} — {}\n",
+            clip(&member.name, FIELD_CHARS),
+            if member.role.is_empty() {
+                "—".to_string()
+            } else {
+                clip(&member.role, FIELD_CHARS)
+            }
+        ));
+    }
+    if !recent.is_empty() {
+        prompt.push_str("\nRecent lines (newest last):\n");
+        for (speaker, body) in recent.iter().rev() {
+            prompt.push_str(&format!(
+                "{}: {}\n",
+                clip(speaker, 40),
+                clip(body, LINE_CHARS)
+            ));
+        }
+    }
+    prompt.push_str("\nNewest message:\n");
+    prompt.push_str(text.trim());
+    prompt.push_str("\n\nNames that should answer:");
+    Ok(prompt)
+}
+
+/// The picker runs on the workspace model unless `LAZYBOY_ROUTER_MODEL` names a
+/// cheaper one; leaving it unset is a valid and common state.
+async fn router_model(state: &AppState, actor: &Actor) -> Result<DynModel, String> {
+    let space = state
+        .db
+        .get_space(actor)
+        .await
+        .map_err(|error| error.to_string())?
+        .ok_or_else(|| "workspace not found".to_string())?;
+    let provider = space
+        .default_model_provider
+        .parse::<ModelProvider>()
+        .map_err(|error| error.to_string())?;
+    let override_id = std::env::var("LAZYBOY_ROUTER_MODEL")
+        .ok()
+        .map(|value| value.trim().to_string())
+        .filter(|value| !value.is_empty());
+    let backend = resolve_backend(ResolveModelRequest {
+        provider,
+        model_id: override_id.or(Some(space.default_model_id)),
+        base_url: space.default_model_base_url.clone(),
+        credentials: CredentialChain {
+            bot: None,
+            space: space.default_model_api_key.clone(),
+            env: credential_from_env(provider),
+        },
+    })
+    .map_err(|error| error.to_string())?;
+    connect_model(&backend).map_err(|error| error.to_string())
+}
+
+/// The single hand-off a bot may pass on: a member it names that is neither
+/// itself nor already working. `@所有人` from a bot is ignored on purpose — a
+/// bot must never broadcast the room.
+pub(crate) async fn handoff_target(
+    state: &AppState,
+    run_id: &str,
+    from_bot_id: &str,
+    body: &str,
+) -> Result<Option<String>, String> {
+    let producing: Option<(String, Option<String>, String)> = sqlx::query_as(
+        "SELECT r.thread_id, t.room_id, r.\"trigger\"
+         FROM runs r JOIN threads t ON t.id=r.thread_id WHERE r.id=$1",
+    )
+    .bind(run_id)
+    .fetch_optional(state.pool())
+    .await
+    .map_err(|error| error.to_string())?;
+    let Some((thread_id, Some(_room_id), trigger)) = producing else {
+        return Ok(None);
+    };
+    // One hop, hard stop: a run that exists because of a hand-off cannot start
+    // another one, or two chatty bots would keep the room (and the bill) alive.
+    if trigger == "handoff" {
+        return Ok(None);
+    }
+    let Some(room) = room_for_thread(state, &thread_id).await? else {
+        return Ok(None);
+    };
+    let mentions = parse_mentions(body, &room.members);
+    if mentions.all || mentions.ids.is_empty() {
+        return Ok(None);
+    }
+    let busy = busy_members(state, &room).await.unwrap_or_default();
+    Ok(mentions
+        .ids
+        .into_iter()
+        .find(|id| id != from_bot_id && !busy.contains(id)))
+}
+
+/// Trim to whole characters so a clipped role or line never splits in half.
+fn clip(text: &str, chars: usize) -> String {
+    text.chars().take(chars).collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn member(id: &str, name: &str) -> Member {
+        Member {
+            id: id.to_string(),
+            name: name.to_string(),
+            role: String::new(),
+        }
+    }
+
+    fn roster() -> Vec<Member> {
+        vec![member("a", "阿明"), member("b", "小美"), member("c", "Dev")]
+    }
+
+    fn ids(values: &[&str]) -> Vec<String> {
+        values.iter().map(|value| value.to_string()).collect()
+    }
+
+    /// Ids in the order they were found. Anything outside the roster is quoted,
+    /// so a failure points at the stranger rather than looking like a member.
+    fn found(picked: &[String], room: &[Member]) -> Vec<String> {
+        picked
+            .iter()
+            .map(|id| {
+                if room.iter().any(|member| member.id == *id) {
+                    id.clone()
+                } else {
+                    format!("«{id}»")
+                }
+            })
+            .collect()
+    }
+
+    #[test]
+    fn only_a_named_member_is_consulted() {
+        let room = roster();
+        let mentions = parse_mentions("@小美 幫我看這份報表", &room);
+        assert!(!mentions.all);
+        assert_eq!(found(&mentions.ids, &room), ["b"]);
+    }
+
+    #[test]
+    fn the_longest_name_wins_when_members_overlap() {
+        let room = vec![member("a", "阿明"), member("b", "阿明哥")];
+        assert_eq!(
+            found(&parse_mentions("@阿明哥 來一下", &room).ids, &room),
+            ["b"]
+        );
+        assert_eq!(
+            found(&parse_mentions("@阿明 來一下", &room).ids, &room),
+            ["a"]
+        );
+    }
+
+    #[test]
+    fn ascii_names_need_a_word_boundary_after_them() {
+        let room = roster();
+        assert_eq!(
+            found(&parse_mentions("@dev 幫我看", &room).ids, &room),
+            ["c"]
+        );
+        assert_eq!(
+            found(&parse_mentions("@Dev, help", &room).ids, &room),
+            ["c"]
+        );
+        assert!(parse_mentions("@Developer 幫我看", &room).ids.is_empty());
+    }
+
+    #[test]
+    fn punctuation_does_not_eat_a_mention() {
+        let room = roster();
+        assert_eq!(
+            found(&parse_mentions("@小美，@阿明 一起看", &room).ids, &room),
+            ["b", "a"]
+        );
+        assert_eq!(found(&parse_mentions("（@小美）", &room).ids, &room), ["b"]);
+    }
+
+    #[test]
+    fn an_email_address_is_not_a_mention() {
+        let room = roster();
+        let mentions = parse_mentions("寄到 mail@小美 或 report@dev.example 就好", &room);
+        assert!(mentions.ids.is_empty() && !mentions.all);
+    }
+
+    #[test]
+    fn naming_everyone_is_the_escape_hatch() {
+        let room = roster();
+        for text in [
+            "@所有人 結論定了",
+            "@全部 來看",
+            "@all look",
+            "@everyone look",
+            "@everybody, your turn",
+        ] {
+            assert!(parse_mentions(text, &room).all, "{text}");
+        }
+        // `@allison` is somebody's name, not `all`.
+        assert!(!parse_mentions("@allison 來了", &room).all);
+    }
+
+    #[test]
+    fn unknown_names_are_dropped_and_repeats_count_once() {
+        let room = roster();
+        let mentions = parse_mentions("@阿明 和 @路人，@阿明 再說一次", &room);
+        assert_eq!(found(&mentions.ids, &room), ["a"]);
+    }
+
+    #[test]
+    fn the_picker_may_answer_in_names_json_or_prose() {
+        let room = roster();
+        assert_eq!(
+            found(&parse_router_reply("小美、阿明", &room), &room),
+            ["b", "a"]
+        );
+        assert_eq!(
+            found(&parse_router_reply("[\"小美\", \"Dev\"]", &room), &room),
+            ["b", "c"]
+        );
+        assert_eq!(
+            found(&parse_router_reply("我覺得小美可以回答", &room), &room),
+            ["b"]
+        );
+    }
+
+    #[test]
+    fn the_picker_cannot_invent_members_or_a_crowd() {
+        let room = roster();
+        assert!(parse_router_reply("NONE", &room).is_empty());
+        assert!(parse_router_reply("請由 Grace 處理", &room).is_empty());
+        assert!(parse_router_reply("Development work", &room).is_empty());
+        let crowd = vec![
+            member("a", "一"),
+            member("b", "二"),
+            member("c", "三"),
+            member("d", "四"),
+        ];
+        assert_eq!(
+            parse_router_reply("一、二、三、四", &crowd).len(),
+            ROUTER_CAP
+        );
+    }
+
+    #[test]
+    fn a_named_member_answers_even_while_the_picker_skips_busy_ones() {
+        let room = roster();
+        let busy = ids(&["b"]);
+        let mentioned = resolve_audience(
+            &room,
+            &Mentions {
+                all: false,
+                ids: ids(&["b"]),
+            },
+            "a",
+            &busy,
+            &[],
+        );
+        assert_eq!(mentioned.targets, ids(&["b"]));
+        assert_eq!(mentioned.reason, Reason::Mention);
+
+        let routed = resolve_audience(&room, &Mentions::default(), "a", &busy, &ids(&["b", "c"]));
+        assert_eq!(routed.targets, ids(&["c"]));
+        assert_eq!(routed.reason, Reason::Routed);
+    }
+
+    #[test]
+    fn everybody_or_nobody_is_settled_without_the_picker() {
+        let room = roster();
+        let all = resolve_audience(
+            &room,
+            &Mentions {
+                all: true,
+                ids: Vec::new(),
+            },
+            "a",
+            &[],
+            &[],
+        );
+        assert_eq!(all.targets, ids(&["a", "b", "c"]));
+        assert_eq!(all.reason, Reason::All);
+
+        // Nothing fitted, the picker named strangers, or it named only busy
+        // members: the host picks it up rather than the message going unread.
+        let stranded: Vec<Vec<String>> = vec![vec![], ids(&["ghost"]), ids(&["b"])];
+        for routed in stranded {
+            let host = resolve_audience(&room, &Mentions::default(), "a", &ids(&["b"]), &routed);
+            assert_eq!(host.targets, ids(&["a"]));
+            assert_eq!(host.reason, Reason::Host);
+        }
+    }
+
+    #[test]
+    fn an_id_that_left_the_room_is_not_an_audience() {
+        let room = roster();
+        let audience = resolve_audience(
+            &room,
+            &Mentions {
+                all: false,
+                ids: ids(&["ghost"]),
+            },
+            "a",
+            &[],
+            &ids(&["c"]),
+        );
+        assert_eq!(audience.targets, ids(&["c"]));
+        assert_eq!(audience.reason, Reason::Routed);
+    }
+
+    #[test]
+    fn clipping_counts_characters_not_bytes() {
+        assert_eq!(clip("群組聊天", 3), "群組聊");
+    }
+}
+
+/// The same decisions with the real tables behind them: how many runs one chat
+/// message is allowed to start, and where a hand-off stops.
+#[cfg(test)]
+mod fan_out {
+    use super::*;
+    use serde_json::json;
+
+    fn app(pool: sqlx::PgPool) -> AppState {
+        AppState {
+            db: crate::db::Db { pool },
+            sandbox: std::sync::Arc::new(lazyboy_sandbox::FakeSandbox::new()),
+            data_dir: String::new(),
+            auth: crate::auth::AuthConfig::from_env(),
+            memory: crate::memory::MemoryService::from_env(),
+            mcp: crate::mcp::McpHub::new(),
+            calls: crate::state::CallRegistry::default(),
+            wakes: crate::state::WakeBus::default(),
+        }
+    }
+
+    /// `members` join one room led by `host`, and share the thread `t`. A
+    /// `group` of one is a direct message, which has no audience to choose.
+    async fn seed(pool: &sqlx::PgPool, members: &[(&str, &str)], host: Option<&str>, group: bool) {
+        sqlx::query("INSERT INTO users (id,name) VALUES ('u','test')")
+            .execute(pool)
+            .await
+            .unwrap();
+        sqlx::query("INSERT INTO spaces (id,user_id,name) VALUES ('s','u','test')")
+            .execute(pool)
+            .await
+            .unwrap();
+        for (id, name) in members {
+            sqlx::query("INSERT INTO bots (id,space_id,user_id,name) VALUES ($1,'s','u',$2)")
+                .bind(id)
+                .bind(name)
+                .execute(pool)
+                .await
+                .unwrap();
+        }
+        if group {
+            sqlx::query(
+                "INSERT INTO rooms (id,space_id,user_id,name,host_bot_id)
+                 VALUES ('r','s','u','產品群',$1)",
+            )
+            .bind(host)
+            .execute(pool)
+            .await
+            .unwrap();
+            for (id, _) in members {
+                sqlx::query("INSERT INTO room_members (room_id,bot_id) VALUES ('r',$1)")
+                    .bind(id)
+                    .execute(pool)
+                    .await
+                    .unwrap();
+            }
+        }
+        sqlx::query(
+            "INSERT INTO threads (id,space_id,user_id,bot_id,room_id) VALUES ('t','s','u',$1,$2)",
+        )
+        .bind(members[0].0)
+        .bind(group.then_some("r"))
+        .execute(pool)
+        .await
+        .unwrap();
+    }
+
+    async fn start_run(pool: &sqlx::PgPool, id: &str, bot: &str, trigger: &str) {
+        sqlx::query(
+            "INSERT INTO runs (id,space_id,user_id,bot_id,thread_id,status,trigger,prompt)
+             VALUES ($1,'s','u',$2,'t','running',$3,'開始')",
+        )
+        .bind(id)
+        .bind(bot)
+        .bind(trigger)
+        .execute(pool)
+        .await
+        .unwrap();
+    }
+
+    async fn runs_for(pool: &sqlx::PgPool, bot: &str) -> i64 {
+        sqlx::query_scalar("SELECT count(*) FROM runs WHERE bot_id=$1")
+            .bind(bot)
+            .fetch_one(pool)
+            .await
+            .unwrap()
+    }
+
+    /// The audience written next to the newest message of `role`. Empty means
+    /// nothing was recorded, which is what a direct message must do.
+    async fn audience_of(pool: &sqlx::PgPool, role: &str) -> Vec<String> {
+        let stored: Option<Option<Vec<String>>> =
+            sqlx::query_scalar("SELECT reply_bot_ids FROM messages WHERE role=$1 LIMIT 1")
+                .bind(role)
+                .fetch_optional(pool)
+                .await
+                .unwrap();
+        stored.flatten().unwrap_or_default()
+    }
+
+    const TRIO: [(&str, &str); 3] = [("a", "阿明"), ("b", "小美"), ("c", "阿強")];
+
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn only_the_member_named_in_the_message_is_woken(pool: sqlx::PgPool) {
+        seed(&pool, &TRIO, Some("a"), true).await;
+        let actor = Actor {
+            user_id: "u".into(),
+            space_id: "s".into(),
+        };
+        crate::runs::send(
+            &app(pool.clone()),
+            &actor,
+            "a",
+            "t",
+            "@小美 幫我看這份",
+            None,
+            &[],
+            &[],
+        )
+        .await
+        .unwrap();
+        assert_eq!(runs_for(&pool, "b").await, 1);
+        assert_eq!(runs_for(&pool, "a").await, 0);
+        assert_eq!(runs_for(&pool, "c").await, 0);
+        assert_eq!(audience_of(&pool, "user").await, ["b"]);
+    }
+
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn a_two_member_room_answers_without_calling_the_picker(pool: sqlx::PgPool) {
+        seed(&pool, &[("a", "阿明"), ("b", "小美")], Some("a"), true).await;
+        let actor = Actor {
+            user_id: "u".into(),
+            space_id: "s".into(),
+        };
+        crate::runs::send(
+            &app(pool.clone()),
+            &actor,
+            "a",
+            "t",
+            "誰幫我看這份",
+            None,
+            &[],
+            &[],
+        )
+        .await
+        .unwrap();
+        assert_eq!(runs_for(&pool, "a").await, 1);
+        assert_eq!(runs_for(&pool, "b").await, 0);
+        assert_eq!(audience_of(&pool, "user").await, ["a"]);
+    }
+
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn a_mention_is_queued_behind_the_work_already_running(pool: sqlx::PgPool) {
+        seed(&pool, &TRIO, Some("a"), true).await;
+        start_run(&pool, "busy", "b", "message").await;
+        let actor = Actor {
+            user_id: "u".into(),
+            space_id: "s".into(),
+        };
+        crate::runs::send(
+            &app(pool.clone()),
+            &actor,
+            "a",
+            "t",
+            "@小美 再看一次",
+            None,
+            &[],
+            &[],
+        )
+        .await
+        .unwrap();
+        assert_eq!(runs_for(&pool, "b").await, 2);
+    }
+
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn a_bot_hands_one_item_over_and_stops_there(pool: sqlx::PgPool) {
+        seed(&pool, &TRIO, Some("a"), true).await;
+        start_run(&pool, "r1", "a", "message").await;
+        let app = app(pool.clone());
+        crate::runs::append_bot_message_with(
+            &app,
+            "t",
+            "r1",
+            "a",
+            "這塊我不熟，@小美 交給妳。",
+            json!([]),
+        )
+        .await
+        .unwrap();
+        let passed: Vec<(String, String)> =
+            sqlx::query_as("SELECT bot_id, \"trigger\" FROM runs WHERE id<>'r1'")
+                .fetch_all(&pool)
+                .await
+                .unwrap();
+        assert_eq!(passed, vec![("b".to_string(), "handoff".to_string())]);
+        assert_eq!(audience_of(&pool, "assistant").await, ["b"]);
+
+        // The hand-off's own reply starts nothing: one hop is the whole budget,
+        // or two chatty bots would keep the room and the bill alive.
+        let handed_run: String = sqlx::query_scalar("SELECT id FROM runs WHERE id<>'r1'")
+            .fetch_one(&pool)
+            .await
+            .unwrap();
+        crate::runs::append_bot_message_with(
+            &app,
+            "t",
+            &handed_run,
+            "b",
+            "@阿強 換妳。",
+            json!([]),
+        )
+        .await
+        .unwrap();
+        let total: i64 = sqlx::query_scalar("SELECT count(*) FROM runs")
+            .fetch_one(&pool)
+            .await
+            .unwrap();
+        assert_eq!(total, 2);
+    }
+
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn a_busy_member_is_not_handed_more_work(pool: sqlx::PgPool) {
+        seed(&pool, &TRIO, Some("a"), true).await;
+        start_run(&pool, "busy", "b", "message").await;
+        start_run(&pool, "r1", "a", "message").await;
+        crate::runs::append_bot_message_with(
+            &app(pool.clone()),
+            "t",
+            "r1",
+            "a",
+            "@小美 或 @阿強，誰有空？",
+            json!([]),
+        )
+        .await
+        .unwrap();
+        let passed: Vec<String> =
+            sqlx::query_scalar("SELECT bot_id FROM runs WHERE \"trigger\"='handoff'")
+                .fetch_all(&pool)
+                .await
+                .unwrap();
+        assert_eq!(passed, vec!["c".to_string()]);
+    }
+
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn a_bot_naming_everyone_hands_over_nothing(pool: sqlx::PgPool) {
+        seed(&pool, &TRIO, Some("a"), true).await;
+        start_run(&pool, "r1", "a", "message").await;
+        crate::runs::append_bot_message_with(
+            &app(pool.clone()),
+            "t",
+            "r1",
+            "a",
+            "@所有人 一起看這份。",
+            json!([]),
+        )
+        .await
+        .unwrap();
+        let total: i64 = sqlx::query_scalar("SELECT count(*) FROM runs")
+            .fetch_one(&pool)
+            .await
+            .unwrap();
+        assert_eq!(total, 1);
+    }
+
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn a_direct_message_never_broadcasts(pool: sqlx::PgPool) {
+        seed(&pool, &[("a", "阿明"), ("b", "小美")], None, false).await;
+        start_run(&pool, "r1", "a", "message").await;
+        crate::runs::append_bot_message_with(
+            &app(pool.clone()),
+            "t",
+            "r1",
+            "a",
+            "@小美 @所有人 一起看。",
+            json!([]),
+        )
+        .await
+        .unwrap();
+        let total: i64 = sqlx::query_scalar("SELECT count(*) FROM runs")
+            .fetch_one(&pool)
+            .await
+            .unwrap();
+        assert_eq!(total, 1);
+        assert!(audience_of(&pool, "assistant").await.is_empty());
+    }
+
+    /// A one-to-one thread has no room to look up; the send must simply reach
+    /// its bot. This once failed before the message was even written, because a
+    /// NULL `room_id` was decoded as if it could not be NULL.
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn a_direct_message_reaches_its_bot_and_records_no_audience(pool: sqlx::PgPool) {
+        seed(&pool, &[("a", "阿明")], None, false).await;
+        let actor = Actor {
+            user_id: "u".into(),
+            space_id: "s".into(),
+        };
+        crate::runs::send(
+            &app(pool.clone()),
+            &actor,
+            "a",
+            "t",
+            "幫我看這份",
+            None,
+            &[],
+            &[],
+        )
+        .await
+        .unwrap();
+        assert_eq!(runs_for(&pool, "a").await, 1);
+        assert!(audience_of(&pool, "user").await.is_empty());
+    }
+
+    /// A room whose host was deleted (or that predates the column) still has a
+    /// host: the first member, as before.
+    #[sqlx::test(migrations = "../../migrations")]
+    async fn a_room_without_a_recorded_host_falls_back_to_its_first_member(pool: sqlx::PgPool) {
+        seed(&pool, &[("a", "阿明"), ("b", "小美")], None, true).await;
+        let room = room_for_thread(&app(pool.clone()), "t")
+            .await
+            .unwrap()
+            .expect("the thread belongs to a room");
+        assert_eq!(room.host_id, "a");
+    }
+}
diff --git a/crates/api/src/runs.rs b/crates/api/src/runs.rs
index 2bea22a..38fa825 100644
--- a/crates/api/src/runs.rs
+++ b/crates/api/src/runs.rs
@@ -106,6 +106,25 @@ pub async fn send(
     let stored_body = crate::attachments::caption_for_title(text, &decoded);
     let mut stored_blocks = blocks.to_vec();
     stored_blocks.extend(crate::attachments::stored_blocks(&decoded));
+    // Who answers is decided before the row lock: an `@name` settles it for
+    // free, and the one model call that sometimes stands in for it must never
+    // hold this thread's transaction open.
+    let room = crate::routing::room_for_thread(state, thread_id).await?;
+    // One run per chosen member — `@name` wins, then the picker's short list,
+    // then the host. A room message keeps this list with it so the chat can say
+    // who is about to talk; a direct message records nothing extra.
+    let mut member_ids: Vec<String> = match room.as_ref() {
+        Some(room) => {
+            crate::routing::audience_for(state, actor, room, thread_id, text)
+                .await
+                .targets
+        }
+        None => vec![bot_id.to_string()],
+    };
+    if member_ids.is_empty() {
+        member_ids.push(bot_id.to_string());
+    }
+    let reply_bot_ids: Option<Vec<String>> = room.map(|_| member_ids.clone());
     let mut tx = state
         .pool()
         .begin()
@@ -199,8 +218,8 @@ pub async fn send(
     .await
     .map_err(|error| error.to_string())?;
     sqlx::query(
-        "INSERT INTO messages (id,thread_id,seq,role,body,blocks,run_id,client_nonce)
-         VALUES ($1,$2,$3,'user',$4,$5,$6,$7)",
+        "INSERT INTO messages (id,thread_id,seq,role,body,blocks,run_id,client_nonce,reply_bot_ids)
+         VALUES ($1,$2,$3,'user',$4,$5,$6,$7,$8)",
     )
     .bind(&message_id)
     .bind(thread_id)
@@ -209,6 +228,7 @@ pub async fn send(
     .bind(json!(stored_blocks))
     .bind(&run_id)
     .bind(client_nonce)
+    .bind(&reply_bot_ids)
     .execute(&mut *tx)
     .await
     .map_err(|error| error.to_string())?;
@@ -220,18 +240,6 @@ pub async fn send(
             .await
             .map_err(|error| error.to_string())?;
     }
-    let mut member_ids: Vec<String> = if let Some(room_id) = room_id.as_deref() {
-        sqlx::query_scalar("SELECT bot_id FROM room_members WHERE room_id=$1 ORDER BY created_at")
-            .bind(room_id)
-            .fetch_all(&mut *tx)
-            .await
-            .map_err(|error| error.to_string())?
-    } else {
-        vec![bot_id.to_string()]
-    };
-    if member_ids.is_empty() {
-        member_ids.push(bot_id.to_string());
-    }
     for (index, member_id) in member_ids.iter().enumerate() {
         if merged && index == 0 {
             continue;
@@ -280,7 +288,15 @@ pub async fn send(
             "SELECT EXISTS(SELECT 1 FROM runs WHERE bot_id=$1 AND id<>$2
              AND status IN ('queued','leased','running','waiting_input','waiting_takeover'))",
         )
-        .bind(bot_id)
+        // The question is about the bot that will actually answer, which in a
+        // room is whoever routing put first — not the host the message was
+        // addressed to.
+        .bind(
+            member_ids
+                .first()
+                .cloned()
+                .unwrap_or_else(|| bot_id.to_string()),
+        )
         .bind(&run_id)
         .fetch_one(&mut *tx)
         .await
@@ -860,7 +876,7 @@ async fn execute_run(
     .unwrap_or_default();
     if !room_mates.is_empty() {
         preamble.push_str(&format!(
-            "\n\nYou are {} in a group chat with: {}. Reply as yourself only. Other agents' lines are prefixed with [Name]. Do not speak for them.",
+            "\n\nYou are {} in a group chat with: {}. Reply as yourself only. Other agents' lines are prefixed with [Name]. Do not speak for them. The human names who should answer: speak when your name is on the message, stay quiet when it is not. When the piece belongs to someone else, say one short line and name them with @TheirName, which hands this one item over once.",
             bot.name,
             room_mates.join("、")
         ));
@@ -2091,6 +2107,15 @@ pub(crate) async fn append_bot_message_with(
     if body.trim().is_empty() && !has_blocks {
         return Ok(());
     }
+    // A bot that names a member may hand this piece over: one hop only, and
+    // never to a member who is already working. The lookup happens before the
+    // transaction so the message write stays short.
+    let handoff = crate::routing::handoff_target(state, run_id, bot_id, body)
+        .await
+        .unwrap_or_else(|error| {
+            tracing::warn!("room hand-off lookup for run {run_id}: {error}");
+            None
+        });
     let mut tx = state
         .pool()
         .begin()
@@ -2106,8 +2131,8 @@ pub(crate) async fn append_bot_message_with(
     .map_err(|error| error.to_string())?;
     let message_id = Uuid::new_v4().to_string();
     sqlx::query(
-        "INSERT INTO messages (id,thread_id,seq,role,body,blocks,run_id,speaker_bot_id)
-         VALUES ($1,$2,$3,'assistant',$4,$5,$6,$7)",
+        "INSERT INTO messages (id,thread_id,seq,role,body,blocks,run_id,speaker_bot_id,reply_bot_ids)
+         VALUES ($1,$2,$3,'assistant',$4,$5,$6,$7,$8)",
     )
     .bind(&message_id)
     .bind(thread_id)
@@ -2116,9 +2141,37 @@ pub(crate) async fn append_bot_message_with(
     .bind(&blocks)
     .bind(run_id)
     .bind(bot_id)
+    .bind(handoff.clone().map(|target| vec![target]))
     .execute(&mut *tx)
     .await
     .map_err(|error| error.to_string())?;
+    if let Some(target) = handoff.as_ref() {
+        let owner: Option<(String, String, String)> = sqlx::query_as(
+            "SELECT r.space_id, r.user_id, b.name
+             FROM runs r JOIN bots b ON b.id=r.bot_id WHERE r.id=$1",
+        )
+        .bind(run_id)
+        .fetch_optional(&mut *tx)
+        .await
+        .map_err(|error| error.to_string())?;
+        if let Some((space_id, user_id, speaker)) = owner {
+            tracing::info!(run_id, target, "room hand-off queued");
+            sqlx::query(
+                "INSERT INTO runs (id,space_id,bot_id,thread_id,user_id,status,trigger,prompt,checkpoint)
+                 VALUES ($1,$2,$3,$4,$5,'queued','handoff',$6,$7)",
+            )
+            .bind(Uuid::new_v4().to_string())
+            .bind(space_id)
+            .bind(target)
+            .bind(thread_id)
+            .bind(user_id)
+            .bind(format!("{speaker} 在群組裡把這件事交給你：\n{body}"))
+            .bind(json!({"handoffFrom": run_id}))
+            .execute(&mut *tx)
+            .await
+            .map_err(|error| error.to_string())?;
+        }
+    }
     tx.commit().await.map_err(|error| error.to_string())?;
     let _ = crate::sessions::append_event(
         state,
diff --git a/crates/api/src/sessions.rs b/crates/api/src/sessions.rs
index 52f6e2f..64d6f35 100644
--- a/crates/api/src/sessions.rs
+++ b/crates/api/src/sessions.rs
@@ -485,6 +485,7 @@ type MessageWithSpeakerRow = (
     Option<String>,
     Option<String>,
     Option<String>,
+    Value,
 );
 
 pub async fn messages_for_session(
@@ -494,7 +495,16 @@ pub async fn messages_for_session(
 ) -> Result<Vec<SessionMessage>, ApiError> {
     let rows: Vec<MessageWithSpeakerRow> = sqlx::query_as(
         "SELECT m.id, m.thread_id, m.seq, m.role, m.body, m.blocks, m.run_id,
-                m.client_nonce, m.created_at, m.speaker_bot_id, b.name, b.avatar_color, b.avatar_shape
+                m.client_nonce, m.created_at, m.speaker_bot_id, b.name, b.avatar_color, b.avatar_shape,
+                COALESCE((
+                    SELECT jsonb_agg(
+                               jsonb_build_object('id', r.id, 'name', r.name,
+                                                  'avatarColor', r.avatar_color,
+                                                  'avatarShape', r.avatar_shape)
+                               ORDER BY picked.ord)
+                      FROM unnest(m.reply_bot_ids) WITH ORDINALITY AS picked(bot_id, ord)
+                      JOIN bots r ON r.id = picked.bot_id
+                ), '[]'::jsonb) AS reply_bots
          FROM messages m
          JOIN threads t ON t.id=m.thread_id
          LEFT JOIN bots b ON b.id=m.speaker_bot_id
@@ -523,6 +533,8 @@ pub async fn messages_for_session(
             speaker_name: row.10,
             speaker_color: row.11,
             speaker_shape: row.12,
+            // A malformed array must not take the whole transcript with it.
+            reply_bots: serde_json::from_value(row.13).unwrap_or_default(),
         })
         .collect())
 }
diff --git a/crates/contracts/src/room.rs b/crates/contracts/src/room.rs
index 94cb36d..3a018ea 100644
--- a/crates/contracts/src/room.rs
+++ b/crates/contracts/src/room.rs
@@ -16,6 +16,9 @@ pub struct Room {
     pub id: String,
     pub name: String,
     pub members: Vec<RoomMember>,
+    /// The member that answers what nobody was named for. `None` means "the
+    /// first member", which is what rooms used before this column resolve to.
+    pub host_bot_id: Option<String>,
     pub last_message_at: Option<DateTime<Utc>>,
     pub last_preview: Option<String>,
     pub unread_count: i64,
@@ -26,6 +29,18 @@ pub struct Room {
 pub struct CreateRoomInput {
     pub name: String,
     pub member_ids: Vec<String>,
+    /// Optional from the first version: leaving it out makes the first member
+    /// the host, which is what a group needs by default.
+    #[serde(default)]
+    pub host_bot_id: Option<String>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct UpdateRoomInput {
+    /// Must be one of the room's members.
+    #[serde(default)]
+    pub host_bot_id: Option<String>,
 }
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
diff --git a/crates/contracts/src/session.rs b/crates/contracts/src/session.rs
index 2bd2a13..dc043ab 100644
--- a/crates/contracts/src/session.rs
+++ b/crates/contracts/src/session.rs
@@ -2,6 +2,8 @@ use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
+use crate::RoomMember;
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct Session {
@@ -46,6 +48,10 @@ pub struct SessionMessage {
     pub speaker_name: Option<String>,
     pub speaker_color: Option<String>,
     pub speaker_shape: Option<String>,
+    /// Who the group decided should answer this message, in order. Empty for a
+    /// one-to-one conversation and for messages written before routing existed.
+    #[serde(default)]
+    pub reply_bots: Vec<RoomMember>,
 }
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
diff --git a/docs/operations.md b/docs/operations.md
index 769ad8a..a29c919 100644
--- a/docs/operations.md
+++ b/docs/operations.md
@@ -59,6 +59,7 @@
 | `LAZYBOY_COMPUTER_SUDO` | 容器內免密碼 sudo；重建桌面容器後生效 | `false` |
 | `LAZYBOY_COMPUTER_DRIVER` | 只支援 `cua`。舊後端已移除；更新映像後需重建桌面容器。 | `cua` |
 | `LAZYBOY_MEMORY_ENABLED` | 長期記憶 | `true` |
+| `LAZYBOY_ROUTER_MODEL` | 群組沒被點名時挑人回覆用的模型；留空沿用空間預設 | 空間預設 |
 
 完整清單與保留政策請見 [`.env.example`](../.env.example)。
 
@@ -136,6 +137,25 @@ LAZYBOY_RUN_HARD_MINUTES=240 # 時間保險絲
 
 真的很久的工作（大計畫、批量資料處理）不該塞在一個 run 裡，改用排程工作分段跑，比較容易驗證也比較省 token。
 
+## 群組聊天：誰說話
+
+群組不是廣播。訊息進來的當下就決定好誰要回覆，其他人不被叫醒，也就不會各打一輪模型。
+
+- `@名字` 是指令：只有被點名的人回。`@所有人`（`@全部`、`@all`、`@everyone`）才是全員出動，這是唯一的逃生口。
+- 沒被點名時，由一個模型照成員的工作內容與簡介挑人，最多三個；只有兩個人的群組不挑，直接由主持人回答。
+- 挑不到人、模型不能用、或挑超過 1.2 秒，一律由主持人接手。訊息不會默默消失——被無視比多回一句更糟。
+- 回覆的人可以交接一次：它在訊息裡 `@某個成員`，系統就替對方排一個 run。交接而來的 run 不能再交接，兩個愛聊的機器人不會把群組和帳單一起撐爆。
+- 主持人預設是群組第一位成員，對話頁上方點主持人名字就能換人，沒有群組設定頁要翻。
+
+決定寫進 `messages.reply_bot_ids`（訊息旁邊會顯示「由誰回覆」「交接給誰」），並記進 api 日誌：
+
+```text
+INFO room routing room=… thread=… reason=mention targets=["01…"]
+```
+
+`reason` 只有四種：`all`（@所有人）、`mention`（點名）、`routed`（模型挑的）、`host`（沒人接，主持人上）。
+挑人用的模型是 `LAZYBOY_ROUTER_MODEL`，留空沿用空間預設；它只影響挑人這一句，回覆本身照各成員自己的模型。
+
 ## 容器內終端機
 
 Agent 透過 Cua 操作 VNC 上的真實終端機。`session` 指定持續使用的視窗；`command` 輸入命令，
diff --git a/image/computer/Dockerfile b/image/computer/Dockerfile
index 65c84af..db00eb8 100644
--- a/image/computer/Dockerfile
+++ b/image/computer/Dockerfile
@@ -5,7 +5,8 @@
 # Build from the repository root:
 #   docker build -f image/computer/Dockerfile -t lazyboy/computer:local .
 
-FROM rust:1-bookworm AS controld
+# Pinned; must satisfy the workspace rust-version in Cargo.toml.
+FROM rust:1.98.1-bookworm AS controld
 WORKDIR /src
 COPY Cargo.toml Cargo.lock ./
 COPY .cargo .cargo
@@ -43,13 +44,30 @@ RUN --mount=type=cache,target=/usr/local/cargo/registry,sharing=locked \
     && cp target/release/cua-driver /cua-driver
 
 FROM debian:bookworm-slim
+ARG TARGETARCH
 
 # Keep Chromium, XFCE, CJK, AT-SPI, git. Skip Debian novnc (pulls nodejs) and
 # fonts-noto-core (Latin is DejaVu/Liberation/huninn).
-RUN printf '%s\n' \
+# dpkg never unpacks docs/man/info/foreign locales; zh_TW catalogs are kept so
+# XFCE menus are in Traditional Chinese. apt lists/archives live in cache
+# mounts, so nothing has to be removed from the layer afterwards.
+# Only Papirus (base) + Papirus-Dark icons are used; the Dark variant symlinks
+# into the base set, so the other variants are dead weight (~60 MB).
+RUN --mount=type=cache,id=lazyboy-apt-cache-$TARGETARCH,target=/var/cache/apt,sharing=locked \
+    --mount=type=cache,id=lazyboy-apt-lists-$TARGETARCH,target=/var/lib/apt,sharing=locked \
+    rm -f /etc/apt/apt.conf.d/docker-clean \
+  && printf '%s\n' \
+      'path-exclude=/usr/share/doc/*' \
+      'path-include=/usr/share/doc/*/copyright' \
+      'path-exclude=/usr/share/man/*' \
+      'path-exclude=/usr/share/info/*' \
+      'path-exclude=/usr/share/gtk-doc/*' \
+      'path-exclude=/usr/share/backgrounds/*' \
+      'path-exclude=/usr/share/locale/*' \
+      'path-include=/usr/share/locale/locale.alias' \
       'path-include=/usr/share/locale/zh_TW/*' \
       'path-include=/usr/share/locale/zh/*' \
-      > /etc/dpkg/dpkg.cfg.d/zz-lazyboy-locale \
+      > /etc/dpkg/dpkg.cfg.d/zz-lazyboy-slim \
   && apt-get update && apt-get install -y --no-install-recommends \
     ca-certificates \
     chromium \
@@ -65,11 +83,9 @@ RUN printf '%s\n' \
     procps \
     python3 \
     sudo \
-    tmux \
     gosu \
     util-linux \
     websockify \
-    wmctrl \
     x11-utils \
     x11vnc \
     xdg-utils \
@@ -83,6 +99,8 @@ RUN printf '%s\n' \
     thunar \
     adwaita-icon-theme \
     gnome-themes-extra \
+    arc-theme \
+    papirus-icon-theme \
     librsvg2-common \
     at-spi2-core \
     libatk-adaptor \
@@ -96,33 +114,50 @@ RUN printf '%s\n' \
   && echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen \
   && locale-gen \
   && mkdir -p /usr/share/novnc \
-  && rm -rf /var/lib/apt/lists/* /var/cache/apt/archives/* /usr/share/doc/* /usr/share/man/* \
-       /usr/share/i18n /usr/share/info /usr/share/gtk-doc /usr/share/backgrounds \
+  && rm -rf /usr/share/i18n /usr/share/icons/ePapirus /usr/share/icons/ePapirus-Dark /usr/share/icons/Papirus-Light \
+  && test -e /usr/share/icons/Papirus-Dark/48x48/apps/utilities-terminal.svg \
+  && test -e /usr/share/icons/Papirus-Dark/48x48/apps/web-browser.svg \
+  && test -d /usr/share/themes/Arc-Dark/xfwm4 \
   && find /usr -name __pycache__ -type d -prune -exec rm -rf '{}' + \
   && find /usr -name '*.py[co]' -delete
 
-# jf open 粉圓 (system UI) + MesloLGS NF (Powerlevel10k glyphs, CJK via fontconfig).
+# MesloLGS NF (Powerlevel10k glyphs, CJK via fontconfig). Pinned to a
+# powerlevel10k-media commit; jf open 粉圓 (system UI) is the same verified
+# file the Cua stage embeds, copied below.
+ARG MESLO_BASE=https://raw.githubusercontent.com/romkatv/powerlevel10k-media/145eb9fbc2f42ee408dacd9b22d8e6e0e553f83d
 RUN mkdir -p /usr/share/fonts/truetype/huninn /usr/share/fonts/truetype/meslo \
-  && curl -fsSL -o /usr/share/fonts/truetype/huninn/jf-openhuninn-2.1.ttf \
-      https://github.com/justfont/open-huninn-font/releases/download/v2.1/jf-openhuninn-2.1.ttf \
-  && curl -fsSL -o "/usr/share/fonts/truetype/meslo/MesloLGS NF Regular.ttf" \
-      "https://github.com/romkatv/powerlevel10k-media/raw/master/MesloLGS%20NF%20Regular.ttf" \
-  && curl -fsSL -o "/usr/share/fonts/truetype/meslo/MesloLGS NF Bold.ttf" \
-      "https://github.com/romkatv/powerlevel10k-media/raw/master/MesloLGS%20NF%20Bold.ttf" \
-  && curl -fsSL -o "/usr/share/fonts/truetype/meslo/MesloLGS NF Italic.ttf" \
-      "https://github.com/romkatv/powerlevel10k-media/raw/master/MesloLGS%20NF%20Italic.ttf" \
-  && curl -fsSL -o "/usr/share/fonts/truetype/meslo/MesloLGS NF Bold Italic.ttf" \
-      "https://github.com/romkatv/powerlevel10k-media/raw/master/MesloLGS%20NF%20Bold%20Italic.ttf" \
-  && fc-cache -f
+  && cd /usr/share/fonts/truetype/meslo \
+  && curl -fsSL -o "MesloLGS NF Regular.ttf" "$MESLO_BASE/MesloLGS%20NF%20Regular.ttf" \
+  && curl -fsSL -o "MesloLGS NF Bold.ttf" "$MESLO_BASE/MesloLGS%20NF%20Bold.ttf" \
+  && curl -fsSL -o "MesloLGS NF Italic.ttf" "$MESLO_BASE/MesloLGS%20NF%20Italic.ttf" \
+  && curl -fsSL -o "MesloLGS NF Bold Italic.ttf" "$MESLO_BASE/MesloLGS%20NF%20Bold%20Italic.ttf" \
+  && printf '%s\n' \
+      'd97946186e97f8d7c0139e8983abf40a1d2d086924f2c5dbf1c29bd8f2c6e57d  MesloLGS NF Regular.ttf' \
+      'b6c0199cf7c7483c8343ea020658925e6de0aeb318b89908152fcb4d19226003  MesloLGS NF Bold.ttf' \
+      '6f357bcbe2597704e157a915625928bca38364a89c22a4ac36e7a116dcd392ef  MesloLGS NF Italic.ttf' \
+      '56b4131adecec052c4b324efb818dd326d586dbc316fc68f98f1cae2eb8d1220  MesloLGS NF Bold Italic.ttf' \
+      | sha256sum -c
+COPY --from=cua_driver --chmod=644 /tmp/huninn.ttf /usr/share/fonts/truetype/huninn/jf-openhuninn-2.1.ttf
+RUN fc-cache -f
 
-RUN git clone --depth=1 https://github.com/romkatv/powerlevel10k.git /usr/share/zsh-theme-powerlevel10k \
-  && git clone --depth=1 https://github.com/zsh-users/zsh-autosuggestions.git /usr/share/zsh/plugins/zsh-autosuggestions \
-  && git clone --depth=1 https://github.com/zsh-users/zsh-syntax-highlighting.git /usr/share/zsh/plugins/zsh-syntax-highlighting \
-  && git clone --depth=1 https://github.com/agkozak/zsh-z.git /usr/share/zsh/plugins/zsh-z \
-  && rm -rf /usr/share/zsh-theme-powerlevel10k/.git \
-            /usr/share/zsh/plugins/zsh-autosuggestions/.git \
-            /usr/share/zsh/plugins/zsh-syntax-highlighting/.git \
-            /usr/share/zsh/plugins/zsh-z/.git
+# zsh prompt + plugins from pinned release tarballs (reproducible, no build-time git).
+RUN set -e; mkdir -p /tmp/zsh /usr/share/zsh/plugins; \
+  fetch() { \
+    curl -fsSL -o "/tmp/zsh/$1.tar.gz" "$2" \
+    && echo "$3  /tmp/zsh/$1.tar.gz" | sha256sum -c \
+    && mkdir -p "$4" && tar -xzf "/tmp/zsh/$1.tar.gz" --strip-components=1 -C "$4"; \
+  }; \
+  fetch powerlevel10k https://codeload.github.com/romkatv/powerlevel10k/tar.gz/refs/tags/v1.20.0 \
+    d8187d44b697b3a37a8c4896678b4380e717cbf2850179529358348780a2d3d7 /usr/share/zsh-theme-powerlevel10k; \
+  fetch zsh-autosuggestions https://codeload.github.com/zsh-users/zsh-autosuggestions/tar.gz/refs/tags/v0.7.1 \
+    0df7affff21cd87ed298e6a3970ed08a1dd66a6efa676454ee5b091ad503badf /usr/share/zsh/plugins/zsh-autosuggestions; \
+  fetch zsh-syntax-highlighting https://codeload.github.com/zsh-users/zsh-syntax-highlighting/tar.gz/refs/tags/0.8.0 \
+    5981c19ebaab027e356fe1ee5284f7a021b89d4405cc53dc84b476c3aee9cc32 /usr/share/zsh/plugins/zsh-syntax-highlighting; \
+  fetch zsh-z https://codeload.github.com/agkozak/zsh-z/tar.gz/102fb78036ed76feedf623907483691777a1d510 \
+    90edc058f50447d27915accd18e022b4059fbaf1d1b34408034fb8f14eba5b9b /usr/share/zsh/plugins/zsh-z; \
+  rm -rf /tmp/zsh; \
+  test -f /usr/share/zsh-theme-powerlevel10k/powerlevel10k.zsh-theme; \
+  test -f /usr/share/zsh/plugins/zsh-z/zsh-z.plugin.zsh
 
 RUN useradd --create-home --uid 1000 --shell /bin/zsh lazyboy \
     && mkdir -p /home/lazyboy /tmp/lazyboy /usr/share/lazyboy/skel /usr/share/lazyboy/xfce-skel /etc/gtk-3.0 /etc/fonts/conf.d \
@@ -153,6 +188,7 @@ COPY --chmod=644 image/computer/xfce/xfce4-panel.xml /usr/share/lazyboy/xfce-ske
 COPY --chmod=644 image/computer/xfce/xfwm4.xml /usr/share/lazyboy/xfce-skel/xfce4/xfconf/xfce-perchannel-xml/xfwm4.xml
 COPY --chmod=644 image/computer/xfce/xfce4-desktop.xml /usr/share/lazyboy/xfce-skel/xfce4/xfconf/xfce-perchannel-xml/xfce4-desktop.xml
 COPY --chmod=644 image/computer/xfce/thunar.xml /usr/share/lazyboy/xfce-skel/xfce4/xfconf/xfce-perchannel-xml/thunar.xml
+COPY --chmod=644 image/computer/xfce/wallpaper.svg /usr/share/lazyboy/wallpaper.svg
 COPY --chmod=644 image/computer/xfce/terminal.desktop /usr/share/applications/lazyboy-terminal.desktop
 COPY --chmod=644 image/computer/xfce/browser.desktop /usr/share/applications/lazyboy-browser.desktop
 # Traditional Chinese catalogs were retained during package installation.
diff --git a/image/computer/dotfiles/terminalrc b/image/computer/dotfiles/terminalrc
index 8857a89..9e64ce4 100644
--- a/image/computer/dotfiles/terminalrc
+++ b/image/computer/dotfiles/terminalrc
@@ -20,12 +20,12 @@ ScrollingOnOutput=FALSE
 ScrollingOnKeystroke=TRUE
 ScrollingBar=TERMINAL_SCROLLBAR_NONE
 ScrollingLines=20000
-ColorForeground=#e2e8f0
-ColorBackground=#0b1220
-ColorCursor=#7dd3fc
+ColorForeground=#d3dae3
+ColorBackground=#2f343f
+ColorCursor=#5294e2
 ColorBoldUseDefault=FALSE
-ColorBold=#f8fafc
-TabActivityColor=#38bdf8
+ColorBold=#ffffff
+TabActivityColor=#5294e2
 Encoding=UTF-8
 TitleMode=TERMINAL_TITLE_REPLACE
 CommandLoginShell=TRUE
diff --git a/image/computer/gtk3-settings.ini b/image/computer/gtk3-settings.ini
index 4d632e7..5a63f3f 100644
--- a/image/computer/gtk3-settings.ini
+++ b/image/computer/gtk3-settings.ini
@@ -1,5 +1,5 @@
 [Settings]
 gtk-font-name=jf open 粉圓 2.1 12
-gtk-icon-theme-name=Adwaita
-gtk-theme-name=Adwaita-dark
+gtk-icon-theme-name=Papirus-Dark
+gtk-theme-name=Arc-Dark
 gtk-application-prefer-dark-theme=1
diff --git a/image/computer/lazyboy-screen b/image/computer/lazyboy-screen
index 65071ee..dec2ac3 100755
--- a/image/computer/lazyboy-screen
+++ b/image/computer/lazyboy-screen
@@ -56,6 +56,12 @@ hydrate_xfce() {
   if [[ -r /etc/xdg/xfce4/helpers.rc ]]; then
     cp -f /etc/xdg/xfce4/helpers.rc "$xfce_home/.config/xfce4/helpers.rc" || true
   fi
+  # Terminals launched by this desktop (boot, panel, menu) inherit
+  # XDG_CONFIG_HOME=$xfce_home/.config, not $HOME/.config.
+  if [[ -r /usr/share/lazyboy/skel/terminalrc ]]; then
+    mkdir -p "$xfce_home/.config/xfce4/terminal"
+    cp -f /usr/share/lazyboy/skel/terminalrc "$xfce_home/.config/xfce4/terminal/terminalrc" || true
+  fi
 }
 
 wait_display() {
@@ -159,7 +165,6 @@ start_desktop() {
     return 0
   fi
   hydrate_xfce "$xfce_home"
-  DISPLAY="$display" xsetroot -solid "#0f172a" >/dev/null 2>&1 || true
   export DISPLAY="$display"
   export XDG_CONFIG_HOME="$xfce_home/.config"
   export XDG_CACHE_HOME="$xfce_home/.cache"
diff --git a/image/computer/xfce/helpers.rc b/image/computer/xfce/helpers.rc
index 4430fb3..2e06195 100644
--- a/image/computer/xfce/helpers.rc
+++ b/image/computer/xfce/helpers.rc
@@ -1,4 +1,3 @@
 WebBrowser=lazyboy-browser
-MailReader=thunderbird
 TerminalEmulator=lazyboy-terminal
 FileManager=thunar
diff --git a/image/computer/xfce/wallpaper.svg b/image/computer/xfce/wallpaper.svg
new file mode 100644
index 0000000..687bed4
--- /dev/null
+++ b/image/computer/xfce/wallpaper.svg
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" width="1920" height="1200" viewBox="0 0 1920 1200">
+  <defs>
+    <linearGradient id="base" x1="0" y1="0" x2="1" y2="1">
+      <stop offset="0" stop-color="#383c4a"/>
+      <stop offset="0.55" stop-color="#2f343f"/>
+      <stop offset="1" stop-color="#1b1e24"/>
+    </linearGradient>
+    <radialGradient id="glowBlue" cx="0.78" cy="0.22" r="0.55">
+      <stop offset="0" stop-color="#5294e2" stop-opacity="0.38"/>
+      <stop offset="0.5" stop-color="#5294e2" stop-opacity="0.10"/>
+      <stop offset="1" stop-color="#5294e2" stop-opacity="0"/>
+    </radialGradient>
+    <radialGradient id="glowTeal" cx="0.12" cy="0.88" r="0.5">
+      <stop offset="0" stop-color="#4dd0c4" stop-opacity="0.22"/>
+      <stop offset="0.6" stop-color="#4dd0c4" stop-opacity="0.05"/>
+      <stop offset="1" stop-color="#4dd0c4" stop-opacity="0"/>
+    </radialGradient>
+  </defs>
+  <rect width="1920" height="1200" fill="url(#base)"/>
+  <rect width="1920" height="1200" fill="url(#glowBlue)"/>
+  <rect width="1920" height="1200" fill="url(#glowTeal)"/>
+  <g fill="none" stroke="#5294e2" stroke-opacity="0.16" stroke-width="2">
+    <circle cx="1500" cy="260" r="220"/>
+    <circle cx="1500" cy="260" r="340"/>
+    <circle cx="1500" cy="260" r="470"/>
+  </g>
+  <g fill="none" stroke="#ffffff" stroke-opacity="0.05" stroke-width="1.5">
+    <path d="M0 900 C 400 780, 800 1020, 1200 880 S 1700 760, 1920 840"/>
+    <path d="M0 980 C 420 860, 820 1100, 1220 960 S 1720 840, 1920 920"/>
+  </g>
+</svg>
diff --git a/image/computer/xfce/xfce4-desktop.xml b/image/computer/xfce/xfce4-desktop.xml
index 15e41b7..620c3ed 100644
--- a/image/computer/xfce/xfce4-desktop.xml
+++ b/image/computer/xfce/xfce4-desktop.xml
@@ -18,16 +18,32 @@
     <property name="show-icons" type="bool" value="true"/>
     <property name="show-workspace-names" type="bool" value="false"/>
   </property>
+  <!-- Xvfb's RANDR output is named "screen", so xfdesktop reads monitorscreen;
+       monitor0 covers displays that report a numbered output. -->
   <property name="backdrop" type="empty">
     <property name="screen0" type="empty">
+      <property name="monitorscreen" type="empty">
+        <property name="workspace0" type="empty">
+          <property name="color-style" type="int" value="0"/>
+          <property name="image-style" type="int" value="5"/>
+          <property name="last-image" type="string" value="/usr/share/lazyboy/wallpaper.svg"/>
+          <property name="rgba1" type="array">
+            <value type="double" value="0.184314"/>
+            <value type="double" value="0.203922"/>
+            <value type="double" value="0.247059"/>
+            <value type="double" value="1"/>
+          </property>
+        </property>
+      </property>
       <property name="monitor0" type="empty">
         <property name="workspace0" type="empty">
           <property name="color-style" type="int" value="0"/>
-          <property name="image-style" type="int" value="0"/>
+          <property name="image-style" type="int" value="5"/>
+          <property name="last-image" type="string" value="/usr/share/lazyboy/wallpaper.svg"/>
           <property name="rgba1" type="array">
-            <value type="double" value="0.0588235"/>
-            <value type="double" value="0.0901961"/>
-            <value type="double" value="0.164706"/>
+            <value type="double" value="0.184314"/>
+            <value type="double" value="0.203922"/>
+            <value type="double" value="0.247059"/>
             <value type="double" value="1"/>
           </property>
         </property>
diff --git a/image/computer/xfce/xfce4-panel.xml b/image/computer/xfce/xfce4-panel.xml
index 44bf455..6994372 100644
--- a/image/computer/xfce/xfce4-panel.xml
+++ b/image/computer/xfce/xfce4-panel.xml
@@ -5,11 +5,11 @@
     <value type="int" value="1"/>
     <property name="dark-mode" type="bool" value="true"/>
     <property name="panel-1" type="empty">
-      <property name="position" type="string" value="p=8;x=640;y=798"/>
+      <property name="position" type="string" value="p=8;x=640;y=782"/>
       <property name="length" type="uint" value="100"/>
       <property name="position-locked" type="bool" value="true"/>
-      <property name="size" type="uint" value="40"/>
-      <property name="icon-size" type="uint" value="24"/>
+      <property name="size" type="uint" value="36"/>
+      <property name="icon-size" type="uint" value="22"/>
       <property name="background-style" type="uint" value="0"/>
       <property name="autohide-behavior" type="uint" value="0"/>
       <property name="mode" type="uint" value="0"/>
@@ -25,13 +25,14 @@
   <property name="plugins" type="empty">
     <property name="plugin-1" type="string" value="applicationsmenu">
       <property name="show-generic-names" type="bool" value="false"/>
+      <property name="show-button-icon" type="bool" value="true"/>
       <property name="show-button-title" type="bool" value="true"/>
       <property name="button-title" type="string" value="應用程式"/>
     </property>
     <property name="plugin-2" type="string" value="tasklist">
       <property name="show-handle" type="bool" value="false"/>
       <property name="show-labels" type="bool" value="true"/>
-      <property name="flat-buttons" type="bool" value="false"/>
+      <property name="flat-buttons" type="bool" value="true"/>
       <property name="grouping" type="uint" value="0"/>
       <property name="include-all-workspaces" type="bool" value="true"/>
     </property>
diff --git a/image/computer/xfce/xfwm4.xml b/image/computer/xfce/xfwm4.xml
index 936f98d..13a3955 100644
--- a/image/computer/xfce/xfwm4.xml
+++ b/image/computer/xfce/xfwm4.xml
@@ -14,7 +14,7 @@
     <property name="snap_to_windows" type="bool" value="true"/>
     <property name="title_font" type="string" value="jf open 粉圓 2.1 11"/>
     <property name="button_layout" type="string" value="O|HMC"/>
-    <property name="theme" type="string" value="Default"/>
+    <property name="theme" type="string" value="Arc-Dark"/>
     <property name="double_click_action" type="string" value="maximize"/>
   </property>
 </channel>
diff --git a/migrations/018_room_routing.sql b/migrations/018_room_routing.sql
new file mode 100644
index 0000000..14d1348
--- /dev/null
+++ b/migrations/018_room_routing.sql
@@ -0,0 +1,20 @@
+-- Group routing: an explicit host, and the audience resolved per message.
+-- A room used to wake every member for every message; the audience is now
+-- decided once when the message arrives, so it is stored with the message.
+
+ALTER TABLE rooms
+    ADD COLUMN IF NOT EXISTS host_bot_id TEXT REFERENCES bots (id) ON DELETE SET NULL;
+
+ALTER TABLE messages
+    ADD COLUMN IF NOT EXISTS reply_bot_ids TEXT[];
+
+-- Existing rooms keep today's behaviour: the first member is the host.
+UPDATE rooms
+   SET host_bot_id = (
+           SELECT m.bot_id
+             FROM room_members m
+            WHERE m.room_id = rooms.id
+            ORDER BY m.created_at, m.bot_id
+            LIMIT 1
+       )
+ WHERE host_bot_id IS NULL;
diff --git a/migrations/019_memory_scope_on_change.sql b/migrations/019_memory_scope_on_change.sql
new file mode 100644
index 0000000..96e2c3c
--- /dev/null
+++ b/migrations/019_memory_scope_on_change.sql
@@ -0,0 +1,73 @@
+-- Deleting a conversation that holds a remembered message used to fail.
+--
+-- `DELETE FROM threads` cascades in two steps that Postgres runs one after the
+-- other: the thread's messages are removed first, and only then is
+-- memory_items.session_id set to NULL. That second step fires this guard while
+-- source_message_id still points at a message that is already gone, so the
+-- guard raised "memory message is outside agent scope" and the delete rolled
+-- back — the human saw a conversation that could not be removed.
+--
+-- The guard now checks only the references that this write actually changes.
+-- A referential action that clears one column leaves the others as they were,
+-- and those were validated when they were written. An INSERT, or a move to
+-- another agent/space/user, still validates everything; pointing the item at a
+-- different session re-checks that its run and message belong to that session.
+-- The same race exists for runs (also removed with the thread), so clearing
+-- session_id never re-checks the run or message.
+CREATE OR REPLACE FUNCTION validate_memory_item_scope() RETURNS trigger AS $$
+DECLARE
+    moved BOOLEAN := TG_OP = 'INSERT'
+        OR NEW.bot_id IS DISTINCT FROM OLD.bot_id
+        OR NEW.space_id IS DISTINCT FROM OLD.space_id
+        OR NEW.user_id IS DISTINCT FROM OLD.user_id;
+    resessioned BOOLEAN := TG_OP = 'UPDATE'
+        AND NEW.session_id IS NOT NULL
+        AND NEW.session_id IS DISTINCT FROM OLD.session_id;
+BEGIN
+    IF NEW.session_id IS NOT NULL
+       AND (moved OR resessioned)
+       AND NOT EXISTS (
+        SELECT 1 FROM threads t
+        WHERE t.id = NEW.session_id AND (
+            (t.room_id IS NULL AND t.bot_id = NEW.bot_id)
+            OR EXISTS (
+                SELECT 1 FROM rooms room JOIN room_members member ON member.room_id=room.id
+                WHERE room.id=t.room_id AND member.bot_id=NEW.bot_id
+                  AND room.space_id=NEW.space_id AND room.user_id=NEW.user_id
+            )
+          )
+          AND t.space_id = NEW.space_id AND t.user_id = NEW.user_id
+    ) THEN
+        RAISE EXCEPTION 'memory session is outside agent scope';
+    END IF;
+    IF NEW.source_run_id IS NOT NULL
+       AND (moved OR resessioned OR NEW.source_run_id IS DISTINCT FROM OLD.source_run_id)
+       AND NOT EXISTS (
+        SELECT 1 FROM runs r
+        WHERE r.id = NEW.source_run_id AND r.bot_id = NEW.bot_id
+          AND r.space_id = NEW.space_id AND r.user_id = NEW.user_id
+          AND (NEW.session_id IS NULL OR r.thread_id = NEW.session_id)
+    ) THEN
+        RAISE EXCEPTION 'memory run is outside agent scope';
+    END IF;
+    IF NEW.source_message_id IS NOT NULL
+       AND (moved OR resessioned OR NEW.source_message_id IS DISTINCT FROM OLD.source_message_id)
+       AND NOT EXISTS (
+        SELECT 1 FROM messages m
+        JOIN threads t ON t.id = m.thread_id
+        WHERE m.id = NEW.source_message_id AND (
+            (t.room_id IS NULL AND t.bot_id = NEW.bot_id)
+            OR EXISTS (
+                SELECT 1 FROM rooms room JOIN room_members member ON member.room_id=room.id
+                WHERE room.id=t.room_id AND member.bot_id=NEW.bot_id
+                  AND room.space_id=NEW.space_id AND room.user_id=NEW.user_id
+            )
+          )
+          AND t.space_id = NEW.space_id AND t.user_id = NEW.user_id
+          AND (NEW.session_id IS NULL OR t.id = NEW.session_id)
+    ) THEN
+        RAISE EXCEPTION 'memory message is outside agent scope';
+    END IF;
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
diff --git a/tests/frontend.test.mjs b/tests/frontend.test.mjs
index a2fb306..9b51080 100644
--- a/tests/frontend.test.mjs
+++ b/tests/frontend.test.mjs
@@ -439,7 +439,7 @@ test('a burst of session events settles into one refresh',()=>{
 
 test('chat follows the event stream instead of a fixed two second poll',()=>{
   const app=fs.readFileSync('apps/web/src/App.tsx','utf8');
-  assert.match(app,/subscribeToSession\(activeSessionId,\(\)=>settle\.kick\(\)/);
+  assert.match(app,/subscribeToSession\(activeSessionId,event=>\{[^}]*settle\.kick\(\)\}/,'every non-streaming event kicks the settle coalescer');
   assert.match(app,/createCoalescer\(\(\)=>\{if\(!document\.hidden\)refresh\(\)\.catch\(\(\)=>\{\}\)\},EVENT_SETTLE_MS\)/);
   assert.match(app,/document\.addEventListener\("visibilitychange",resume\)/);
   assert.doesNotMatch(app,/const timer=setInterval\(\(\)=>\{refresh\(\)/,'the 2s transcript poll should be gone');
@@ -622,3 +622,93 @@ for(const hostUpdatesDuringReconnect of [false,true])test(`reconnect preserves s
   assert.equal(instances.at(-1).viewOnly,false,'a handoff made mid-reconnect still owns the new session');
   assert.equal(instances.at(-1).focused,true,'taking over lands the first keystroke');
 });
+
+// Who speaks in a room is decided by three small pure functions, so the `@`
+// list is run rather than read: which token the caret is writing, who that token
+// could mean, and what the composer holds after a pick.
+const mentionsJs=ts.transpileModule(fs.readFileSync('apps/web/src/mentions.ts','utf8'),{compilerOptions:{module:ts.ModuleKind.CommonJS}}).outputText;
+const mentionsBox={exports:{},require:()=>{throw new Error('unexpected import')}};
+vm.runInNewContext(mentionsJs,mentionsBox);
+const {mentionToken,mentionChoices,acceptMention}=mentionsBox.exports;
+const EVERYONE='所有人';
+const roster=[{id:'b1',name:'小美'},{id:'b2',name:'Alex'},{id:'b3',name:'Alexa'},{id:'b4',name:'工程小助手'}];
+// The list is built inside a vm, so its arrays are not this realm's arrays:
+// compare what a person sees (names, joined) rather than the objects themselves.
+const names=(token,source=roster)=>mentionChoices(token,source,EVERYONE).map(choice=>choice.name).join(',');
+
+test('a mention list opens only on the token under the caret',()=>{
+  assert.equal(mentionToken('@',1),'','a bare @ is still a list, not a word');
+  assert.equal(mentionToken('@小美',3),'小美');
+  assert.equal(mentionToken('嗨 @小美 @',7),'','the last word wins, the earlier mention is spent');
+  assert.equal(mentionToken('@小美 幫我看',4),null,'a finished name closes the list');
+  assert.equal(mentionToken('幫我改一下佈景',6),null,'plain text offers nobody');
+  assert.equal(mentionToken('mail@example.com',16),null,'an email address is not a mention');
+  assert.equal(mentionToken('@@',2),null,'a doubled @ is a typo, not a name');
+});
+
+test('the whole-room escape hatch is the first name you are offered',()=>{
+  const open=mentionChoices('',roster,EVERYONE);
+  assert.equal(open[0].name,EVERYONE,'@ comes with the escape hatch on top');
+  assert.equal(open[0].member,null,'it reaches the room, so it is nobody in particular');
+  assert.equal(names('').split(',').length,roster.length+1,'then the whole room, in order');
+  assert.equal(names('').split(',')[1],roster[0].name);
+  assert.equal(names('所'),EVERYONE,'a token that cannot grow into 所有人 drops it');
+  assert.equal(names(EVERYONE).split(',')[0],EVERYONE,'typing it out keeps it offered');
+});
+
+test('mention choices match loosely and stay one glance long',()=>{
+  assert.equal(names('alex'),'Alex,Alexa','case does not matter, room order does');
+  assert.equal(names('小'),'小美,工程小助手','a name anywhere in the word hits');
+  assert.equal(names(' nobody '),'','a token nobody can answer to offers nobody');
+  const crowd=Array.from({length:9},(_,index)=>({id:`b${index}`,name:`bot${index}`}));
+  assert.equal(names('',crowd).split(',').length,6,'six rows is the cap');
+  assert.equal(names('',crowd).split(',')[0],EVERYONE,'and the escape hatch still leads');
+});
+
+test('accepting a mention leaves the sentence readable and the list closed',()=>{
+  const fresh=acceptMention('@',1,'小美');
+  assert.equal(fresh.text,'@小美 ');
+  assert.equal(fresh.caret,fresh.text.length,'the caret sits past the space, so typing continues the sentence');
+  assert.equal(mentionToken(fresh.text,fresh.caret),null,'and the list does not reopen behind it');
+  const picked=acceptMention('幫我 @小 部署',5,'小美');
+  assert.ok(picked.text.startsWith('幫我 @小美 '),'only the typed token is replaced');
+  assert.ok(picked.text.includes('部署'),'the rest of the message survives');
+  assert.equal(acceptMention('@小',2,'小美').text,'@小美 ','a half-typed name is replaced whole');
+});
+
+// When a message was said is split the way chat apps split it: the day once,
+// as a divider, and the clock time on each message. The words for today and
+// yesterday come from the catalog; everything else is the locale's own spelling.
+const chatTimeJs=ts.transpileModule(fs.readFileSync('apps/web/src/chat-time.ts','utf8'),{compilerOptions:{module:ts.ModuleKind.CommonJS}}).outputText;
+const chatTimeBox={exports:{},require:()=>{throw new Error('unexpected import')}};
+vm.runInNewContext(chatTimeJs,chatTimeBox);
+const {dayLabel,sameDay,clockTime}=chatTimeBox.exports;
+const words={today:zhTW.today,yesterday:zhTW.yesterday};
+// A Wednesday afternoon, built in local time so the calendar day is unambiguous.
+const now=new Date(2026,9,7,15,30);
+const daysAgo=(count,hour=9)=>new Date(2026,9,7-count,hour);
+
+test('a day is named the way people say it',()=>{
+  assert.equal(dayLabel(daysAgo(0,0),now,'zh-TW',words),'今天','midnight still counts as today');
+  assert.equal(dayLabel(daysAgo(0,23),now,'zh-TW',words),'今天','a message later today is still today, not the future');
+  assert.equal(dayLabel(daysAgo(1,23),now,'zh-TW',words),'昨天','yesterday means the calendar day, not 24 hours');
+  assert.equal(dayLabel(daysAgo(1),now,'en',{today:en.today,yesterday:en.yesterday}),'Yesterday');
+  assert.equal(dayLabel(daysAgo(2),now,'zh-TW',words),'星期一','the past week goes by weekday');
+  assert.equal(dayLabel(daysAgo(6),now,'zh-TW',words),'星期四','six days back is the last weekday');
+  const week=dayLabel(daysAgo(7),now,'zh-TW',words);
+  assert.match(week,/9\/30|9月30日/,'a week or more ago is written as a date');
+  assert.match(week,/週三|星期三/,'with its weekday, so it reads like a chat and not a form');
+  assert.ok(!/2026/.test(week),'this year is not spelled out');
+  assert.match(dayLabel(new Date(2025,9,1),now,'zh-TW',words),/2025/,'another year is spelled out');
+  assert.match(dayLabel(new Date(2026,8,15),now,'en',{today:en.today,yesterday:en.yesterday}),/Tue, 9\/15/,'English keeps the same short numeric date');
+  assert.equal(dayLabel('not a date',now,'zh-TW',words),'','garbage shows nothing rather than Invalid Date');
+});
+
+test('messages split by calendar day and show only their clock time',()=>{
+  assert.ok(sameDay(new Date(2026,9,7,0,1),new Date(2026,9,7,23,59)),'first and last minute share a day');
+  assert.ok(!sameDay(new Date(2026,9,7,23,59),new Date(2026,9,8,0,0)),'a minute past midnight is a new day');
+  assert.ok(!sameDay('garbage','garbage'),'two unreadable dates are not the same day');
+  assert.equal(clockTime(new Date(2026,9,7,9,5),'zh-TW'),'09:05','24-hour clock, zero padded');
+  assert.equal(clockTime(new Date(2026,9,7,15,30),'en'),'15:30');
+  assert.equal(clockTime('garbage','en'),'');
+});