cancel lingering MCP session task to prevent event loop spin on exit

Author: anticomputer

src/seclab_taskflow_agent/runner.py

@@ -475,6 +475,14 @@ async def _run_streamed() -> None:
                 continue
             except Exception:
                 logging.exception("Exception in mcp server cleanup task")
+        # Cancel the MCP session task if it's still running to prevent
+        # the asyncio event loop from spinning on a dangling task.
+        if not mcp_sessions.done():
+            mcp_sessions.cancel()
+            try:
+                await mcp_sessions
+            except (asyncio.CancelledError, Exception):
+                pass
 
 
 async def run_main(