fix(test): expect 4404 close code for disabled embedded chat (#38841)

PR #38743 split the dashboard PTY WebSocket refusal codes (4404 = chat
disabled, 4403 = host/origin mismatch — see web_server.py refusal site
comment) but left test_rejects_when_embedded_chat_disabled asserting the
old 4403, so it has expected 4403 while the server sends 4404. Main CI has
been red on test (2)/(4) shards since that commit. Update the assertion to
4404 to match the disabled-chat path.

tests/hermes_cli/test_web_server.py

@@ -3528,7 +3528,7 @@ class TestPtyWebSocket:
         with pytest.raises(WebSocketDisconnect) as exc:
             with self.client.websocket_connect(self._url()):
                 pass
-        assert exc.value.code == 4403
+        assert exc.value.code == 4404
 
     def test_rejects_missing_token(self, monkeypatch):
         monkeypatch.setattr(