fix(tui): tolerate agents without session_cwd in _register_session_cwd; adapt stubs to the cwd kwarg

Workspace moves stamp agent.session_cwd so a lazily started Codex thread
starts in the moved-to directory. Agents that never had the attribute
(test doubles, slotted objects) must keep working, so stamp only when the
attribute exists. Test stubs of _set_session_context mirror the new cwd
kwarg, and the Codex gateway test asserts the contract (no pinned session
cwd) instead of the attribute's absence.

tests/agent/test_codex_app_server_integration.py

@@ -346,7 +346,7 @@ class TestRunConversationCodexPath:
         assert not client_mock.chat.completions.create.called
 
     def test_gateway_terminal_cwd_seeds_codex_thread_cwd(self, monkeypatch, tmp_path):
-        """Gateway sessions set TERMINAL_CWD without stamping agent.session_cwd.
+        """Gateway sessions set TERMINAL_CWD without pinning agent.session_cwd.
         Codex app-server must still start in that configured workspace instead
         of falling back to the Hermes daemon process cwd."""
         from agent.transports.codex_app_server_session import (
@@ -372,7 +372,7 @@ class TestRunConversationCodexPath:
         monkeypatch.setattr(CodexAppServerSession, "run_turn", fake_run_turn)
 
         agent = _make_codex_agent()
-        assert not hasattr(agent, "session_cwd")
+        assert agent.session_cwd is None
         with patch.object(agent, "_spawn_background_review", return_value=None):
             agent.run_conversation("hi")
 

tests/tui_gateway/test_session_db_ownership_teardown.py

@@ -274,7 +274,7 @@ def build_env(monkeypatch, tmp_path):
 
     monkeypatch.setattr("hermes_state_registry.acquire", _factory)
     for name, value in [
-        ("_set_session_context", lambda _key: []),
+        ("_set_session_context", lambda _key, cwd=None: []),
         ("_clear_session_context", lambda _tokens: None),
         ("_wire_callbacks", lambda _sid: None),
         ("_config_model_target", lambda: None),

tui_gateway/session_workdir.py

@@ -197,7 +197,7 @@ def _register_session_cwd(session: dict | None) -> None:
         return
     # Workspace moves must reach lazy/restarted runtimes, not just terminal tools.
     # Do not reinitialize memory providers or invalidate the cached system prompt.
-    if (agent := session.get("agent")) is not None:
+    if hasattr(agent := session.get("agent"), "session_cwd"):
         agent.session_cwd = session.get("cwd") or None
     with contextlib.suppress(Exception):
         from tools.terminal_tool import register_task_env_overrides