fix(chat): 任务暂停不再拦截主 Agent 对话 + 移除乐观回显消除消息错乱

- 后端 chat 处理器去掉 IsPaused 的 409 拒绝(保留 IsDeleting):主 Agent
  编排会话独立于任务暂停,暂停中仍可继续对话;暂停只终止当前进行的那一轮。
- 前端 sessions-tab 删除 chatExtra 乐观回显:主 Agent 控制台改为纯服务端
  数据渲染。根治伪造 seq 撞全局 DB id 导致的 React key 冲突/跨会话内容渗漏,
  以及发送失败不回滚的幽灵气泡。发送失败改为回滚输入框内容 + toast 报错。

Claude-Session: https://claude.ai/code/session_01RVrPtpngE9T9DRJHosf6MB

server/server.go

@@ -1004,7 +1004,9 @@ func (s *Server) control(w http.ResponseWriter, r *http.Request) {
 	case "pause":
 		s.engine.Pause(t.ID, agent.AbortPausedByUser)
 		// Main Agent turns run outside Engine's planner/worker context so they need
-		// their own cancellation. New turns are rejected while the task is paused.
+		// their own cancellation: pausing terminates the CURRENTLY running turn. New
+		// turns are still allowed while paused — the main-agent console is independent
+		// of task pause (the chat handler no longer rejects on IsPaused).
 		s.cancelTaskChat(t.ID, agent.AbortChatPausedWithTask)
 	case "resume":
 		s.engine.Run(s.ctx, t) // ensure loops are alive, then un-pause + nudge
@@ -3117,10 +3119,8 @@ func (s *Server) chat(w http.ResponseWriter, r *http.Request) {
 		writeErr(w, 409, "任务正在删除，无法发送新消息")
 		return
 	}
-	if s.engine.IsPaused(t.ID) {
-		writeErr(w, 409, "任务已暂停，无法发送新消息")
-		return
-	}
+	// 注意:任务暂停(paused)不拦截主 Agent 对话。主 Agent 编排会话独立于 planner/
+	// worker 的暂停,暂停中仍可继续对话(暂停只终止其正在进行的那一轮,见 control())。
 	var req struct {
 		Message     string           `json:"message"`
 		Attachments []chatAttachment `json:"attachments,omitempty"` // 方式1 上传的文件(路径相对任务工作目录)
@@ -3133,9 +3133,9 @@ func (s *Server) chat(w http.ResponseWriter, r *http.Request) {
 	// turn busy before its first activity/file write, including rule-mode turns.
 	// If deletion wins the race, the second barrier check rejects this request.
 	s.chatMu.Lock()
-	if s.engine.IsDeleting(t.ID) || s.engine.IsPaused(t.ID) {
+	if s.engine.IsDeleting(t.ID) {
 		s.chatMu.Unlock()
-		writeErr(w, 409, "任务正在删除或已暂停，无法发送新消息")
+		writeErr(w, 409, "任务正在删除，无法发送新消息")
 		return
 	}
 	if s.chatBusy[t.ID] {

web/src/app/(main)/function/tasks/detail/_tabs/sessions-tab.tsx

@@ -359,8 +359,6 @@ export function SessionsTab({ taskId }: { taskId: string }) {
   const [olderIntents, setOlderIntents] = React.useState<TaskNode[]>([]);
   const [intentsHasMore, setIntentsHasMore] = React.useState(false);
   const [loadingOlderIntents, setLoadingOlderIntents] = React.useState(false);
-  // Local-only chat messages overlaid onto the main-agent transcript.
-  const [chatExtra, setChatExtra] = React.useState<Activity[]>([]);
   const [input, setInput] = React.useState("");
   const [sending, setSending] = React.useState(false);
   const [stopping, setStopping] = React.useState(false);
@@ -613,7 +611,6 @@ export function SessionsTab({ taskId }: { taskId: string }) {
   // ID) resumes from the DB, so a dropped realtime link self-heals; seq-merge dedups.
   React.useEffect(() => {
     setStore({});
-    setChatExtra([]);
     setSseLive(false);
     setActiveId(MAIN_ID); // a stale worker id from the previous task must not leak in
     snapshotRef.current = 0;
@@ -892,13 +889,11 @@ export function SessionsTab({ taskId }: { taskId: string }) {
   // worker session shows only its intent's activity, led by the intent objective.
   const activity = React.useMemo(() => {
     const items = activeState?.items ?? [];
-    if (isMain) {
-      // chatExtra is an optimistic local echo — drop any entry the persisted (SSE)
-      // copy already covers so messages don't show twice after the backend round-trips.
-      const seen = new Set(items.map((a) => `${a.kind} ${a.summary}`));
-      const pending = chatExtra.filter((a) => !seen.has(`${a.kind} ${a.summary}`));
-      return [...items, ...pending].sort((a, b) => a.seq - b.seq);
-    }
+    // The main-agent console renders purely from server data: the human turn is
+    // persisted+broadcast by the backend BEFORE it returns, so it arrives over the
+    // same SSE stream (worker="mainagent") as every agent step — no client-side
+    // optimistic echo, hence no fabricated seq that could collide with real DB ids.
+    if (isMain) return items;
     if (isPlanner || isSystem) return items;
     // Worker session: the intent leads the transcript as a right-aligned "user"-style
     // message (the task handed to this worker), followed by its execution steps.
@@ -918,7 +913,6 @@ export function SessionsTab({ taskId }: { taskId: string }) {
     isPlanner,
     isSystem,
     activeState,
-    chatExtra,
     active.id,
     active.title,
     active.last_activity,
@@ -1021,36 +1015,19 @@ export function SessionsTab({ taskId }: { taskId: string }) {
     const text = input.trim();
     const atts = attachments;
     if ((!text && atts.length === 0) || sending) return;
-    const base = [...(store.main?.items ?? []), ...chatExtra];
-    const nextSeq = Math.max(0, ...base.map((a) => a.seq)) + 1;
-    const userMsg: Activity = {
-      seq: nextSeq,
-      worker: "mainagent",
-      ts: new Date().toISOString(),
-      kind: "user",
-      summary: text,
-      // 有附件时把 {text, attachments} 塞进 detail,乐观气泡直接渲染卡片,无需再拉取。
-      detail: atts.length > 0 ? JSON.stringify({ text, attachments: atts }) : undefined,
-    };
-    // optimistic echo of the human turn only; the agent's steps + final answer
-    // stream back live via SSE (worker="mainagent"), so we don't append the reply.
-    setChatExtra((prev) => [...prev, userMsg]);
+    // No optimistic echo: the backend persists+broadcasts the human turn before it
+    // returns, so it streams back over SSE (worker="mainagent") with its real DB
+    // seq — the transcript renders it from server data like every other step. Clear
+    // the composer eagerly for responsiveness; restore it if the send fails.
     setInput("");
     setAttachments([]);
     setSending(true);
     api
       .chat(text, taskId, atts.length > 0 ? atts : undefined)
-      .catch(() => {
-        setChatExtra((prev) => [
-          ...prev,
-          {
-            seq: nextSeq + 1,
-            worker: "mainagent",
-            ts: new Date().toISOString(),
-            kind: "text",
-            summary: "（发送失败，请稍后重试）",
-          },
-        ]);
+      .catch((e) => {
+        setInput(text); // restore so the user doesn't lose their text / attachments
+        setAttachments(atts);
+        toast.error("发送失败：" + ((e as Error).message || "请稍后重试"));
       })
       .finally(() => setSending(false));
   }