♻️(backend) refactor backend recording state management

Instead of relying on the egress_started event—which fires when egress is
starting, not actually started—I now rely on egress_updated for more accurate
status updates. This is especially important for the active status, which
triggers after egress has truly joined the room. Using this avoids prematurely
stopping client-side listening to room.isRecording updates. A further
refactoring may remove reliance on room updates entirely.

The goal is to minimize handling metadata in the mediator class. egress_starting
is still used for simplicity, but egress_started could be considered in the
future.

Note: if the API to start egress hasn’t responded yet, the webhook may fail to
find the recording because it currently matches by worker ID. This is unstable.
A better approach would be to pass the database ID in the egress metadata and
recover the recording from it in the webhook.

src/backend/core/tests/recording/worker/test_mediator.py

@@ -122,10 +122,7 @@ def test_mediator_start_recording_from_forbidden_status(
     mock_update_room_metadata.assert_not_called()
 
 
-@mock.patch("core.utils.update_room_metadata")
-def test_mediator_stop_recording_success(
-    mock_update_room_metadata, mediator, mock_worker_service
-):
+def test_mediator_stop_recording_success(mediator, mock_worker_service):
     """Test successful recording stop"""
     # Setup
     mock_recording = RecordingFactory(
@@ -143,15 +140,8 @@ def test_mediator_stop_recording_success(
     mock_recording.refresh_from_db()
     assert mock_recording.status == RecordingStatusChoices.STOPPED
 
-    mock_update_room_metadata.assert_called_once_with(
-        str(mock_recording.room.id), {"recording_status": "saving"}
-    )
 
-
-@mock.patch("core.utils.update_room_metadata")
-def test_mediator_stop_recording_aborted(
-    mock_update_room_metadata, mediator, mock_worker_service
-):
+def test_mediator_stop_recording_aborted(mediator, mock_worker_service):
     """Test recording stop when worker returns ABORTED"""
     # Setup
     mock_recording = RecordingFactory(
@@ -166,15 +156,10 @@ def test_mediator_stop_recording_aborted(
     mock_recording.refresh_from_db()
     assert mock_recording.status == RecordingStatusChoices.ABORTED
 
-    mock_update_room_metadata.assert_called_once_with(
-        str(mock_recording.room.id), {"recording_status": "saving"}
-    )
-
 
 @pytest.mark.parametrize("error_class", [WorkerConnectionError, WorkerResponseError])
-@mock.patch("core.utils.update_room_metadata")
 def test_mediator_stop_recording_worker_errors(
-    mock_update_room_metadata, mediator, mock_worker_service, error_class
+    mediator, mock_worker_service, error_class
 ):
     """Test handling of worker errors during stop"""
     # Setup
@@ -190,5 +175,3 @@ def test_mediator_stop_recording_worker_errors(
     # Verify recording updates
     mock_recording.refresh_from_db()
     assert mock_recording.status == RecordingStatusChoices.FAILED_TO_STOP
-
-    mock_update_room_metadata.assert_not_called()

src/backend/core/tests/services/test_livekit_events.py

@@ -94,22 +94,55 @@ def test_handle_egress_ended_success(
     assert recording.status == "stopped"
 
 
+@pytest.mark.parametrize(
+    ("egress_status", "status"),
+    (
+        (EgressStatus.EGRESS_ACTIVE, "started"),
+        (EgressStatus.EGRESS_ENDING, "saving"),
+        (EgressStatus.EGRESS_ABORTED, "aborted"),
+    ),
+)
 @mock.patch("core.utils.update_room_metadata")
-def test_handle_egress_started_success(mock_update_room_metadata, service):
-    """Should successfully start recording and update room's metadata."""
+def test_handle_egress_updated_success(
+    mock_update_room_metadata, egress_status, status, service
+):
+    """Should successfully update room's metadata."""
 
     recording = RecordingFactory(worker_id="worker-1", status="initiated")
     mock_data = mock.MagicMock()
     mock_data.egress_info.egress_id = recording.worker_id
-    mock_data.egress_info.status = EgressStatus.EGRESS_ACTIVE
+    mock_data.egress_info.status = egress_status
 
-    service._handle_egress_started(mock_data)
+    service._handle_egress_updated(mock_data)
 
     mock_update_room_metadata.assert_called_once_with(
-        str(recording.room.id), {"recording_status": "started"}
+        str(recording.room.id), {"recording_status": status}
     )
 
 
+@pytest.mark.parametrize(
+    "egress_status",
+    (
+        EgressStatus.EGRESS_FAILED,
+        EgressStatus.EGRESS_LIMIT_REACHED,
+    ),
+)
+@mock.patch("core.utils.update_room_metadata")
+def test_handle_egress_updated_non_handled(
+    mock_update_room_metadata, egress_status, service
+):
+    """Should ignore certain egress status and don't trigger metadata updates."""
+
+    recording = RecordingFactory(worker_id="worker-1", status="initiated")
+    mock_data = mock.MagicMock()
+    mock_data.egress_info.egress_id = recording.worker_id
+    mock_data.egress_info.status = egress_status
+
+    service._handle_egress_updated(mock_data)
+
+    mock_update_room_metadata.assert_not_called()
+
+
 @pytest.mark.parametrize(
     ("mode", "notification_type"),
     (