fix: restore timeout and fix celery test infrastructure

- Re-add timeout=1.0 to ws_manager pubsub loop (prevents CPU spin)
- Use Redis for Celery tests (memory:// broker doesn't support chords)
- Add timeout param to in-memory subscriber mock
- Remove duplicate celery_includes fixture from rtc_ws tests

server/tests/test_transcripts_rtc_ws.py

@@ -115,9 +115,7 @@ def appserver(tmpdir, setup_database, celery_session_app, celery_session_worker)
     settings.DATA_DIR = DATA_DIR
 
 
-@pytest.fixture(scope="session")
-def celery_includes():
-    return ["reflector.pipelines.main_live_pipeline"]
+# Using celery_includes from conftest.py which includes both pipelines
 
 
 @pytest.mark.usefixtures("setup_database")