feat: 命令台子代理链路（主任务/模型子代理/委派子任务 + 过程调用实时同步）

host：链路条目带 thread 归属；delegate 向父链路文件写 agent-start/done 标记。服务端：GET /tasks/{id}/agents 聚合父链路 + 子链路文件成代理链（状态口径：委派以结束标记为准、无标记即进行中；模型子代理无结束信号时父任务运行中为进行中、否则未知）。命令台：新增子代理链路区，随 SSE 流防抖刷新；扁平链路也渲染 agent 标记。

cloud/server.py

@@ -184,6 +184,127 @@ def _read_trace_entries(path):
     except OSError:
         return []
     return entries
+
+
+AGENT_CALL_LIMIT = 1000
+
+
+def _read_agent_entries(path):
+    """读链路文件供子代理聚合：按 (thread, id) 去重，后到的完成态
+    覆盖先到的开始态，保首次顺序；坏行与无 id 行跳过；文件不
+    存在为空。同一 item id 在不同线程出现时不互相覆盖（模型内
+    子代理与主任务各有自己的线程）。"""
+    entries = []
+    index = {}
+    try:
+        with open(path, "r", encoding="utf-8") as f:
+            for line in f:
+                line = line.strip()
+                if not line:
+                    continue
+                try:
+                    entry = json.loads(line)
+                except ValueError:
+                    continue
+                if not isinstance(entry, dict) or "id" not in entry:
+                    continue
+                key = (entry.get("thread") or "", entry["id"])
+                if key in index:
+                    entries[index[key]] = entry
+                else:
+                    index[key] = len(entries)
+                    entries.append(entry)
+    except OSError:
+        return []
+    return entries
+
+
+def _latest_ts(values):
+    vals = [v for v in values if isinstance(v, (int, float))]
+    return max(vals) if vals else None
+
+
+def _agent_status_from_task(status):
+    return {"queued": "running", "running": "running",
+            "completed": "completed", "merged": "completed",
+            "failed": "failed", "merge-failed": "failed",
+            "interrupted": "interrupted"}.get(status, "unknown")
+
+
+def _build_agent_chain(task, trace_dir):
+    """任务 → 子代理链：主任务 + 模型内子代理（同文件多线程）+
+    委派子任务（父链路里的 agent-start/done 标记 + 子链路文件）。
+
+    状态诚实口径：委派子任务以 agent-done 标记为准，无标记即
+    进行中——委派进程与父任务相互独立，父任务结束不代表子任务
+    停；模型内子代理无明确结束信号，父任务运行中即进行中，
+    否则未知。无 thread 的旧条目一律归主任务。
+    """
+    parent_path = os.path.join(
+        trace_dir, _trace_file_name(task["id"]) + ".jsonl")
+    entries = _read_agent_entries(parent_path)
+    calls = [e for e in entries
+             if e.get("kind") not in ("agent-start", "agent-done")]
+    main_thread = None
+    for e in calls:
+        if e.get("thread"):
+            main_thread = e["thread"]
+            break
+    root_calls = [e for e in calls
+                  if not e.get("thread") or e.get("thread") == main_thread]
+    agents = [{
+        "id": "main", "name": "主任务", "kind": "main", "parent": None,
+        "status": _agent_status_from_task(task.get("status")),
+        "prompt": None, "trace": None,
+        "calls": root_calls[:AGENT_CALL_LIMIT],
+        "updated_ts": _latest_ts([e.get("ts") for e in root_calls]),
+    }]
+    task_running = task.get("status") in ("queued", "running")
+    threads = {}
+    for e in calls:
+        t = e.get("thread")
+        if t and t != main_thread:
+            threads.setdefault(t, []).append(e)
+    for t, es in threads.items():
+        agents.append({
+            "id": t, "name": "模型子代理 " + t[:12], "kind": "model",
+            "parent": "main",
+            "status": "running" if task_running else "unknown",
+            "prompt": None, "trace": None,
+            "calls": es[:AGENT_CALL_LIMIT],
+            "updated_ts": _latest_ts([e.get("ts") for e in es]),
+        })
+    starts = {}
+    dones = {}
+    for e in entries:
+        if e.get("kind") == "agent-start" and e.get("name"):
+            starts[e["name"]] = e
+        elif e.get("kind") == "agent-done" and e.get("name"):
+            dones[e["name"]] = e
+    for name, s in starts.items():
+        trace_name = s.get("trace") or dones.get(name, {}).get("trace")
+        child_calls = []
+        if trace_name:
+            child_path = os.path.join(
+                trace_dir, os.path.basename(trace_name))
+            child_calls = [e for e in _read_agent_entries(child_path)
+                           if e.get("kind") not in
+                           ("agent-start", "agent-done")]
+        done = dones.get(name)
+        status = "running"
+        if done and done.get("status") in (
+                "completed", "failed", "interrupted"):
+            status = done["status"]
+        agents.append({
+            "id": "delegate:" + name, "name": name, "kind": "delegate",
+            "parent": "main", "status": status,
+            "prompt": s.get("prompt"), "trace": trace_name,
+            "calls": child_calls[:AGENT_CALL_LIMIT],
+            "updated_ts": _latest_ts(
+                [e.get("ts") for e in child_calls] +
+                [s.get("ts"), done.get("ts") if done else None]),
+        })
+    return agents
 DEFAULT_SWEEP_THRESHOLD_SECONDS = 300
 # 限流默认值：每 IP / 每 API key 每分钟 120 次；环境变量
 # CLOUD_RATE_LIMIT_PER_MINUTE / CLOUD_RATE_LIMIT_WINDOW_SECONDS 可调。
@@ -1262,6 +1383,8 @@ class CloudControlPlaneHandler(BaseHTTPRequestHandler):
                     user_id, rest[: -len("/trace/stream")])
             elif rest.endswith("/trace") and method == "GET":
                 self._task_trace(user_id, rest[: -len("/trace")])
+            elif rest.endswith("/agents") and method == "GET":
+                self._task_agents(user_id, rest[: -len("/agents")])
             elif rest.endswith("/cancel") and method == "POST":
                 self._cancel_task(user_id, rest[: -len("/cancel")])
             elif rest.endswith("/merge") and method == "POST":
@@ -2471,6 +2594,27 @@ class CloudControlPlaneHandler(BaseHTTPRequestHandler):
         self._send_json(200, {"task_id": task_id, "status": task["status"],
                               "entries": entries, "note": note})
 
+    def _task_agents(self, user_id, task_id):
+        row = self._fetch_task(task_id)
+        if row is None:
+            self._send_json(404, {"error": "task not found"})
+            return
+        task = _task_to_dict(row)
+        with _auth_store(self.server.db_path) as store:
+            if not store.check_permission(user_id, task["project_id"], "read"):
+                self._send_json(403, {"error": "forbidden"})
+                return
+        worktree_host = task.get("worktree_host")
+        if worktree_host and worktree_host != socket.gethostname():
+            self._send_json(200, {"task_id": task_id, "status": task["status"],
+                                  "agents": [],
+                                  "note": ("链路文件在 worktree 主机 %s 上，本机读不到"
+                                           % worktree_host)})
+            return
+        agents = _build_agent_chain(task, _trace_dir_for(self.server))
+        self._send_json(200, {"task_id": task_id, "status": task["status"],
+                              "agents": agents, "note": ""})
+
     def _task_trace_stream(self, user_id, task_id):
         row = self._fetch_task(task_id)
         if row is None: