fix: preserve subagent controls across attached session peers

tests/tui_gateway/test_subagent_snapshot.py

@@ -181,8 +181,12 @@ def test_reattach_preserves_child_controls_including_late_registration(runtime,
     popup = type(new)()
     with server._session_resume_lock, owner["history_lock"]:
         server._rebind_live_transport("ui-owner", owner, popup)
+    for peer in (new, popup):
+        assert {r["subagent_id"] for r in call("subagent.list", via=peer)["result"]["subagents"]} == {"before", "after"}
+        assert call("subagent.tail", via=peer, subagent_id="before")["result"]["text"] == "live child output"
     assert server._close_sessions_for_transport(popup) == (0, 0)
-    assert owner["transport"] is new
+    assert server._session_transport_contains(owner, new)
+    assert not server._session_transport_contains(owner, popup)
     assert {row["subagent_id"] for row in call("subagent.list", via=new)["result"]["subagents"]} == {"before", "after"}
     for sid in ("before", "after"):
         assert call("subagent.tail", via=new, subagent_id=sid)["result"]["text"] == "live child output"

tools/delegate_tool_registry.py

@@ -109,6 +109,13 @@ def interrupt_subagent(subagent_id: str) -> bool:
         logger.debug("interrupt_subagent(%s) failed: %s", subagent_id, exc)
         return False
 
+def _subagent_transport_matches(record, transport) -> bool:
+    from tui_gateway.transport import FanoutTransport
+
+    bound = record.get("owner_transport")
+    return bound is transport or (isinstance(bound, FanoutTransport) and bound.contains(transport))
+
+
 def steer_subagent(
     subagent_id: str, text: str, *, owner_session_id: Optional[str] = None, owner_transport: Any = None,
     owner_session_record: Any = None,
@@ -130,7 +137,7 @@ def steer_subagent(
         if owner_session_id is not None and (
             record.get("owner_session_id") != owner_session_id
             or owner_transport is None
-            or record.get("owner_transport") is not owner_transport
+            or not _subagent_transport_matches(record, owner_transport)
             or owner_session_record is None
             or record.get("owner_session_record") is not owner_session_record
         ):

tui_gateway/methods_subagents.py

@@ -17,12 +17,12 @@ _SUBAGENT_TAIL_BYTES = 16384
 
 
 def _owned_subagent_records(session_id, transport, owner):
-    from tools.delegate_tool_registry import _active_subagents, _active_subagents_lock
+    from tools.delegate_tool_registry import _active_subagents, _active_subagents_lock, _subagent_transport_matches
 
     with _active_subagents_lock:
         return [dict(r) for r in _active_subagents.values()
                 if r.get("owner_session_id") == session_id
-                and r.get("owner_transport") is transport
+                and _subagent_transport_matches(r, transport)
                 and r.get("owner_session_record") is owner]
 
 

tui_gateway/session_lifecycle.py

@@ -476,7 +476,7 @@ def _rebind_live_transport(sid: str, session: dict, transport: Transport) -> Non
             if (record.get("owner_session_id") == sid
                     and record.get("owner_session_record") is session
                     and record.get("owner_transport") is not None):
-                record["owner_transport"] = transport
+                record["owner_transport"] = session["transport"]
     # Every transport that showed this session (pop-outs resume the same sid); on disconnect the last
     # viewer becomes the transport instead of the drop sentinel.
     session.setdefault("viewers", {})[transport] = time.time()