fix(cli): ignore CancelledError in background task done callback (#839)

CLI teardown cancels pending sync_entity_vectors tasks; _log_task_failure
treated that as an unhandled callback exception because CancelledError is a
BaseException. Skip cancelled tasks and add regression tests.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: rudi193-cmd

src/basic_memory/deps/services.py

@@ -447,8 +447,12 @@ def schedule(self, task_name: str, **payload: Any) -> None:
 
 
 def _log_task_failure(completed: asyncio.Task) -> None:
+    if completed.cancelled():
+        return
     try:
         completed.result()
+    except asyncio.CancelledError:
+        return
     except Exception as exc:  # pragma: no cover
         logger.exception("Background task failed", error=str(exc))
 

tests/deps/test_task_failure_callback.py

@@ -0,0 +1,38 @@
+"""Tests for background task done-callback error handling."""
+
+import asyncio
+from unittest.mock import patch
+
+import pytest
+
+from basic_memory.deps.services import _log_task_failure
+
+
+@pytest.mark.asyncio
+async def test_log_task_failure_ignores_cancelled_task():
+    async def slow():
+        await asyncio.sleep(10)
+
+    task = asyncio.create_task(slow())
+    task.cancel()
+    with pytest.raises(asyncio.CancelledError):
+        await task
+
+    with patch("basic_memory.deps.services.logger.exception") as mock_exc:
+        _log_task_failure(task)
+        mock_exc.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_log_task_failure_logs_real_exception():
+    async def boom():
+        raise ValueError("sync failed")
+
+    task = asyncio.create_task(boom())
+    with pytest.raises(ValueError):
+        await task
+
+    with patch("basic_memory.deps.services.logger.exception") as mock_exc:
+        _log_task_failure(task)
+        mock_exc.assert_called_once()
+        assert "sync failed" in str(mock_exc.call_args)