fix(flow): 撤销并发限制与会话复用改动

Author: genz27

src/main.py

@@ -144,12 +144,6 @@ async def auto_unban_task():
         await auto_unban_task_handle
     except asyncio.CancelledError:
         pass
-    # Close shared HTTP session pools
-    try:
-        await flow_client.close()
-        print("✓ Flow client HTTP session closed")
-    except Exception as e:
-        print(f"⚠ Flow client close failed: {e}")
     # Close browser if initialized
     if browser_service:
         await browser_service.close()