feat: add broadcast_dag_status, decorator integration, and mixdown progress

- Add broadcast_dag_status() to dag_progress.py: fetches Hatchet run
  details, transforms to DagStatusData, and broadcasts DAG_STATUS event
  via WebSocket. Fire-and-forget with exception swallowing.
- Modify with_error_handling decorator to call broadcast_dag_status on
  both task success and failure.
- Add DAG_STATUS to USER_ROOM_EVENTS (broadcast.py) and reconnect
  filter (transcripts_websocket.py) to avoid replaying stale DAG state.
- Add initial DAG broadcast at workflow dispatch (transcript_process.py).
- Extend make_audio_progress_logger with optional transcript_id param
  for transient DAG_TASK_PROGRESS events during mixdown.
- All deferred imports for fork-safety, all broadcasts fire-and-forget.

server/tests/test_dag_progress.py

@@ -5,8 +5,11 @@ into structured DagTask list for frontend consumption.
 """
 
 from datetime import datetime, timezone
-from unittest.mock import MagicMock
+from unittest.mock import AsyncMock, MagicMock, patch
 
+import pytest
+
+from reflector.hatchet.constants import TaskName
 from reflector.hatchet.dag_progress import (
     DagStatusData,
     DagTask,
@@ -387,3 +390,234 @@ class TestDagStatusData:
         assert dumped["tasks"][0]["name"] == "get_recording"
         assert dumped["tasks"][0]["status"] == "completed"
         assert dumped["tasks"][0]["duration_seconds"] == 1.0
+
+
+class AsyncContextManager:
+    """No-op async context manager for mocking fresh_db_connection."""
+
+    async def __aenter__(self):
+        return None
+
+    async def __aexit__(self, *args):
+        return None
+
+
+class TestBroadcastDagStatus:
+    """Test broadcast_dag_status function.
+
+    broadcast_dag_status uses deferred imports inside its function body.
+    We mock the source modules/objects before calling the function.
+    Importing daily_multitrack_pipeline triggers a cascade
+    (subject_processing -> HatchetClientManager.get_client at module level),
+    so we set _instance before the import to prevent real SDK init.
+    """
+
+    @pytest.fixture(autouse=True)
+    def _setup_hatchet_mock(self):
+        """Set HatchetClientManager._instance to a mock to prevent real SDK init.
+
+        Module-level code in workflow files calls get_client() during import.
+        Setting _instance before import avoids ClientConfig validation.
+        """
+        from reflector.hatchet.client import HatchetClientManager
+
+        original = HatchetClientManager._instance
+        HatchetClientManager._instance = MagicMock()
+        yield
+        HatchetClientManager._instance = original
+
+    @pytest.mark.asyncio
+    async def test_broadcasts_dag_status(self):
+        """broadcast_dag_status fetches run, transforms, and broadcasts."""
+        mock_transcript = MagicMock()
+        mock_transcript.id = "t-123"
+
+        mock_details = _make_details(
+            shape=[_make_shape_item("s1", "get_recording")],
+            tasks=[_make_task_summary("s1", status="COMPLETED")],
+            run_id="wf-abc",
+        )
+
+        mock_client = MagicMock()
+        mock_client.runs.aio_get = AsyncMock(return_value=mock_details)
+
+        with (
+            patch(
+                "reflector.hatchet.client.HatchetClientManager.get_client",
+                return_value=mock_client,
+            ),
+            patch(
+                "reflector.hatchet.broadcast.append_event_and_broadcast",
+                new_callable=AsyncMock,
+            ) as mock_broadcast,
+            patch(
+                "reflector.db.transcripts.transcripts_controller.get_by_id",
+                new_callable=AsyncMock,
+                return_value=mock_transcript,
+            ),
+            patch(
+                "reflector.hatchet.workflows.daily_multitrack_pipeline.fresh_db_connection",
+                return_value=AsyncContextManager(),
+            ),
+        ):
+            from reflector.hatchet.dag_progress import broadcast_dag_status
+
+            await broadcast_dag_status("t-123", "wf-abc")
+
+            mock_client.runs.aio_get.assert_called_once_with("wf-abc")
+            mock_broadcast.assert_called_once()
+            call_args = mock_broadcast.call_args
+            assert call_args[0][0] == "t-123"  # transcript_id
+            assert call_args[0][1] is mock_transcript  # transcript
+            assert call_args[0][2] == "DAG_STATUS"  # event_name
+            data = call_args[0][3]
+            assert data["workflow_run_id"] == "wf-abc"
+            assert len(data["tasks"]) == 1
+
+    @pytest.mark.asyncio
+    async def test_swallows_exceptions(self):
+        """broadcast_dag_status never raises even when internals fail."""
+        from reflector.hatchet.dag_progress import broadcast_dag_status
+
+        with patch(
+            "reflector.hatchet.workflows.daily_multitrack_pipeline.fresh_db_connection",
+            side_effect=RuntimeError("db exploded"),
+        ):
+            # Should not raise
+            await broadcast_dag_status("t-123", "wf-abc")
+
+    @pytest.mark.asyncio
+    async def test_no_broadcast_when_transcript_not_found(self):
+        """broadcast_dag_status does not broadcast if transcript is None."""
+        mock_details = _make_details(
+            shape=[_make_shape_item("s1", "get_recording")],
+            tasks=[_make_task_summary("s1", status="COMPLETED")],
+        )
+
+        mock_client = MagicMock()
+        mock_client.runs.aio_get = AsyncMock(return_value=mock_details)
+
+        with (
+            patch(
+                "reflector.hatchet.client.HatchetClientManager.get_client",
+                return_value=mock_client,
+            ),
+            patch(
+                "reflector.hatchet.workflows.daily_multitrack_pipeline.fresh_db_connection",
+                return_value=AsyncContextManager(),
+            ),
+            patch(
+                "reflector.db.transcripts.transcripts_controller.get_by_id",
+                new_callable=AsyncMock,
+                return_value=None,
+            ),
+            patch(
+                "reflector.hatchet.broadcast.append_event_and_broadcast",
+                new_callable=AsyncMock,
+            ) as mock_broadcast,
+        ):
+            from reflector.hatchet.dag_progress import broadcast_dag_status
+
+            await broadcast_dag_status("t-123", "wf-abc")
+
+            mock_broadcast.assert_not_called()
+
+
+class TestMakeAudioProgressLoggerWithBroadcast:
+    """Test make_audio_progress_logger with transcript_id for transient broadcasts."""
+
+    @pytest.fixture(autouse=True)
+    def _setup_hatchet_mock(self):
+        """Set HatchetClientManager._instance to prevent real SDK init on import."""
+        from reflector.hatchet.client import HatchetClientManager
+
+        original = HatchetClientManager._instance
+        if original is None:
+            HatchetClientManager._instance = MagicMock()
+        yield
+        HatchetClientManager._instance = original
+
+    def test_broadcasts_transient_progress_event(self):
+        """When transcript_id provided and progress_pct not None, broadcasts event."""
+        import asyncio
+
+        from reflector.hatchet.workflows.daily_multitrack_pipeline import (
+            make_audio_progress_logger,
+        )
+
+        ctx = MagicMock()
+        ctx.log = MagicMock()
+
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+
+        mock_broadcast = AsyncMock()
+        tasks_created = []
+
+        original_create_task = loop.create_task
+
+        def capture_create_task(coro):
+            task = original_create_task(coro)
+            tasks_created.append(task)
+            return task
+
+        try:
+            with (
+                patch(
+                    "reflector.hatchet.broadcast.broadcast_event",
+                    mock_broadcast,
+                ),
+                patch.object(loop, "create_task", side_effect=capture_create_task),
+            ):
+                callback = make_audio_progress_logger(
+                    ctx, TaskName.MIXDOWN_TRACKS, interval=0.0, transcript_id="t-123"
+                )
+                callback(50.0, 100.0)
+
+                # Run pending tasks
+                if tasks_created:
+                    loop.run_until_complete(asyncio.gather(*tasks_created))
+
+                mock_broadcast.assert_called_once()
+                event_arg = mock_broadcast.call_args[0][1]
+                assert event_arg.event == "DAG_TASK_PROGRESS"
+                assert event_arg.data["task_name"] == TaskName.MIXDOWN_TRACKS
+                assert event_arg.data["progress_pct"] == 50.0
+        finally:
+            loop.close()
+
+    def test_no_broadcast_without_transcript_id(self):
+        """When transcript_id is None, no broadcast happens."""
+        from reflector.hatchet.workflows.daily_multitrack_pipeline import (
+            make_audio_progress_logger,
+        )
+
+        ctx = MagicMock()
+
+        with patch(
+            "reflector.hatchet.broadcast.broadcast_event",
+            new_callable=AsyncMock,
+        ) as mock_broadcast:
+            callback = make_audio_progress_logger(
+                ctx, TaskName.MIXDOWN_TRACKS, interval=0.0, transcript_id=None
+            )
+            callback(50.0, 100.0)
+            mock_broadcast.assert_not_called()
+
+    def test_no_broadcast_when_progress_pct_is_none(self):
+        """When progress_pct is None, no broadcast happens even with transcript_id."""
+        from reflector.hatchet.workflows.daily_multitrack_pipeline import (
+            make_audio_progress_logger,
+        )
+
+        ctx = MagicMock()
+
+        with patch(
+            "reflector.hatchet.broadcast.broadcast_event",
+            new_callable=AsyncMock,
+        ) as mock_broadcast:
+            callback = make_audio_progress_logger(
+                ctx, TaskName.MIXDOWN_TRACKS, interval=0.0, transcript_id="t-123"
+            )
+            callback(None, 100.0)
+            mock_broadcast.assert_not_called()