refactor: improve session management across worker tasks and pipelines

- Remove "if session" anti-pattern from all functions
- Functions now require explicit AsyncSession parameters instead of optional session_factory
- Worker tasks (Celery) create sessions at top level using session_factory
- Add proper AsyncSession type annotations to all session parameters
- Update cleanup.py: delete_single_transcript, cleanup_old_transcripts, cleanup_old_public_data
- Update process.py: process_recording, process_meetings, reprocess_failed_recordings
- Update ics_sync.py: sync_room_ics, sync_all_ics_calendars, create_upcoming_meetings
- Update pipeline classes: get_transcript methods now require session
- Fix tests to pass sessions correctly

Benefits:
- Better type safety and IDE support with explicit AsyncSession typing
- Clear transaction boundaries with sessions created at task level
- Consistent session management pattern across codebase
- No ambiguity about session vs session_factory usage

server/tests/test_cleanup.py

@@ -15,12 +15,12 @@ from reflector.worker.cleanup import cleanup_old_public_data
 
 
 @pytest.mark.asyncio
-async def test_cleanup_old_public_data_skips_when_not_public():
+async def test_cleanup_old_public_data_skips_when_not_public(session):
     """Test that cleanup is skipped when PUBLIC_MODE is False."""
     with patch("reflector.worker.cleanup.settings") as mock_settings:
         mock_settings.PUBLIC_MODE = False
 
-        result = await cleanup_old_public_data()
+        result = await cleanup_old_public_data(session)
 
         # Should return early without doing anything
         assert result is None
@@ -81,7 +81,7 @@ async def test_cleanup_old_public_data_deletes_old_anonymous_transcripts(session
             mock_delete.return_value = None
 
             # Run cleanup with test session
-            await cleanup_old_public_data(session=session)
+            await cleanup_old_public_data(session)
 
             # Verify only old anonymous transcript was deleted
             assert mock_delete.call_count == 1
@@ -162,7 +162,7 @@ async def test_cleanup_deletes_associated_meeting_and_recording(session):
             mock_storage.return_value.delete_file = AsyncMock()
 
             # Run cleanup with test session
-            await cleanup_old_public_data(session=session)
+            await cleanup_old_public_data(session)
 
             # Verify transcript was deleted
             result = await session.execute(
@@ -226,7 +226,7 @@ async def test_cleanup_handles_errors_gracefully(session):
             mock_delete.side_effect = [Exception("Delete failed"), None]
 
             # Run cleanup with test session - should not raise exception
-            await cleanup_old_public_data(session=session)
+            await cleanup_old_public_data(session)
 
             # Both transcripts should have been attempted to delete
             assert mock_delete.call_count == 2

server/tests/test_pipeline_main_file.py

@@ -624,7 +624,10 @@ async def test_pipeline_file_process_no_transcript():
 
         # Should raise an exception for missing transcript when get_transcript is called
         with pytest.raises(Exception, match="Transcript not found"):
-            await pipeline.get_transcript()
+            from reflector.db import get_session_factory
+
+            async with get_session_factory()() as session:
+                await pipeline.get_transcript(session)
 
 
 @pytest.mark.asyncio