Show threads as compact rows instead of inline full messages

The channel timeline now renders each thread as a single compact row
with sender avatar, message preview (truncated to one line), reply
count with participant avatars, and last reply time. Clicking a row
opens the thread in the right panel where the full conversation lives.
This matches Slack's thread-list pattern instead of dumping every
message body into the channel view.

AgentCompany-New/src/renderer/src/pages/chat/ChatTimeline.tsx

@@ -1,5 +1,5 @@
 import type { ReactNode } from "react";
-import { Button, Icon, Pill } from "../../shared/ui";
+import { Avatar, Button, Icon, Pill } from "../../shared/ui";
 import type {
   ApprovalRecord,
   ChatAttachmentRecord,
@@ -9,8 +9,7 @@ import type {
   ChatThreadRecord,
   FileObjectRecord,
 } from "../../../../shared/domain";
-import { ChatMessageRow } from "./ChatMessageRow";
+import { formatDay, senderName, type MessageContext } from "./chat-helpers";
-import { formatDay, type MessageContext } from "./chat-helpers";
 
 export function ChatTimeline({
   rootMessages,
@@ -49,35 +48,32 @@ export function ChatTimeline({
 }) {
   const elements: ReactNode[] = [];
   let lastDay = "";
-  rootMessages.forEach((message) => {
+  for (const message of rootMessages) {
     const day = formatDay(message.createdAt);
     if (day !== lastDay) {
       lastDay = day;
       elements.push(<DayDivider key={`day-${day}`} label={day} />);
     }
     const thread = threadsInSpace.find((t) => t.rootMessageId === message.id) ?? null;
-    const replyCount = thread
+    const replies = thread
-      ? messagesInSpace.filter((m) => m.threadId === thread.id && m.id !== thread.rootMessageId).length
+      ? messagesInSpace.filter((m) => m.threadId === thread.id && m.id !== thread.rootMessageId)
-      : 0;
+      : [];
+    const lastReply = replies.length > 0 ? replies[replies.length - 1] : null;
+    const participantNames = threadParticipants(replies, context);
     elements.push(
-      <ChatMessageRow
+      <ThreadRow
         key={message.id}
         message={message}
-        attachments={attachments}
+        thread={thread}
-        mentions={mentions}
+        replyCount={replies.length}
-        slashInvocations={slashInvocations}
+        lastReply={lastReply}
-        files={files}
+        participantNames={participantNames}
-        replyCount={replyCount}
-        onOpenThread={thread ? () => onOpenThread(thread.id) : null}
         context={context}
-        canModify={message.senderType === "employee" && message.senderId === currentEmployeeId && !message.deletedAt}
+        onOpen={thread ? () => onOpenThread(thread.id) : null}
-        onEdit={(bodyMd) => onEditMessage(message.id, bodyMd)}
-        onDelete={() => onDeleteMessage(message.id)}
-        onOpenFile={onOpenFile}
       />,
     );
-  });
+  }
-  pendingApprovals.forEach((approval) => {
+  for (const approval of pendingApprovals) {
     elements.push(
       <ApprovalInline
         key={`approval-${approval.id}`}
@@ -86,13 +82,108 @@ export function ChatTimeline({
         onDecline={() => onDecline(approval.id)}
       />,
     );
-  });
+  }
   return <>{elements}</>;
 }
 
+function ThreadRow({
+  message,
+  thread,
+  replyCount,
+  lastReply,
+  participantNames,
+  context,
+  onOpen,
+}: {
+  message: ChatMessageRecord;
+  thread: ChatThreadRecord | null;
+  replyCount: number;
+  lastReply: ChatMessageRecord | null;
+  participantNames: string[];
+  context: MessageContext;
+  onOpen: (() => void) | null;
+}) {
+  const name = senderName(message, context);
+  const bot = message.senderType === "agent";
+  const preview = message.bodyMd.replace(/\n+/g, " ").slice(0, 120);
+  const time = formatTime(message.createdAt);
+  return (
+    <button
+      type="button"
+      onClick={onOpen ?? undefined}
+      style={{
+        display: "flex",
+        alignItems: "flex-start",
+        gap: 10,
+        width: "100%",
+        padding: "10px 12px",
+        border: 0,
+        borderRadius: 8,
+        background: "transparent",
+        cursor: onOpen ? "pointer" : "default",
+        textAlign: "left",
+        transition: "background 0.1s",
+      }}
+      onMouseEnter={(e) => { if (onOpen) e.currentTarget.style.background = "var(--hover)"; }}
+      onMouseLeave={(e) => { e.currentTarget.style.background = "transparent"; }}
+    >
+      <Avatar name={name} size="sm" bot={bot} />
+      <div style={{ flex: 1, minWidth: 0 }}>
+        <div style={{ display: "flex", alignItems: "baseline", gap: 6, marginBottom: 2 }}>
+          <span style={{ fontSize: 13, fontWeight: 560 }}>{name}</span>
+          <span style={{ fontSize: 11, color: "var(--text-4)" }}>{time}</span>
+        </div>
+        <div style={{
+          fontSize: 13,
+          color: "var(--text-2)",
+          overflow: "hidden",
+          textOverflow: "ellipsis",
+          whiteSpace: "nowrap",
+          lineHeight: 1.4,
+        }}>
+          {preview}
+        </div>
+        {replyCount > 0 && (
+          <div style={{ display: "flex", alignItems: "center", gap: 6, marginTop: 4 }}>
+            {participantNames.slice(0, 3).map((n) => (
+              <Avatar key={n} name={n} size="sm" bot />
+            ))}
+            <span style={{ fontSize: 11, color: "var(--accent)", fontWeight: 500 }}>
+              {replyCount} {replyCount === 1 ? "reply" : "replies"}
+            </span>
+            {lastReply && (
+              <span style={{ fontSize: 11, color: "var(--text-4)" }}>
+                {formatTime(lastReply.createdAt)}
+              </span>
+            )}
+          </div>
+        )}
+      </div>
+    </button>
+  );
+}
+
+function threadParticipants(replies: ChatMessageRecord[], context: MessageContext): string[] {
+  const seen = new Set<string>();
+  const names: string[] = [];
+  for (const r of replies) {
+    const key = `${r.senderType}:${r.senderId}`;
+    if (seen.has(key)) continue;
+    seen.add(key);
+    names.push(senderName(r, context));
+  }
+  return names;
+}
+
+function formatTime(iso: string): string {
+  const d = new Date(iso);
+  if (Number.isNaN(d.getTime())) return "";
+  return d.toLocaleTimeString([], { hour: "2-digit", minute: "2-digit", hour12: false });
+}
+
 function DayDivider({ label }: { label: string }) {
   return (
-    <div className="row" style={{ gap: 12, margin: "8px 0 16px" }}>
+    <div className="row" style={{ gap: 12, margin: "8px 0 12px" }}>
       <div style={{ flex: 1, height: 1, background: "var(--border-soft)" }} />
       <div style={{ fontSize: 12, color: "var(--text-3)", fontWeight: 540 }}>{label}</div>
       <div style={{ flex: 1, height: 1, background: "var(--border-soft)" }} />
@@ -110,19 +201,10 @@ function ApprovalInline({
   onDecline: () => void;
 }) {
   return (
-    <div
+    <div style={{ margin: "8px 0 12px 12px", maxWidth: 480, border: "1px solid var(--border-strong)", borderRadius: 12, background: "var(--panel)", padding: 14 }}>
-      style={{
-        margin: "14px 0 18px 44px",
-        maxWidth: 480,
-        border: "1px solid var(--border-strong)",
-        borderRadius: 12,
-        background: "var(--panel)",
-        padding: 14,
-      }}
-    >
       <div className="row" style={{ marginBottom: 8 }}>
         <Icon name="approve" size={14} color="var(--amber)" />
-        <span style={{ fontSize: 12, color: "var(--amber)", fontWeight: 540, letterSpacing: "0.01em" }}>Approval needed</span>
+        <span style={{ fontSize: 12, color: "var(--amber)", fontWeight: 540 }}>Approval needed</span>
         <Pill tone={approval.risk === "high" ? "red" : approval.risk === "medium" ? "amber" : undefined}>{approval.risk}</Pill>
       </div>
       <div style={{ fontSize: 14, fontWeight: 540, marginBottom: 4 }}>{approval.title}</div>