[Code scan] Import logging.handlers before simplify SMTP setup

[njzjz]

This issue is from a Codex global scan of the repository.

simplify.run_iter() crashes when SMTP logging handlers are configured because logging.handlers is not imported.

Evidence:

dpgen/dpgen/simplify/simplify.py

Lines 12 to 16 in 7af5246

	import glob
	import logging
	import os
	import queue
	from collections import defaultdict

dpgen/dpgen/simplify/simplify.py

Lines 538 to 545 in 7af5246

	if mdata.get("handlers", None):
	if mdata["handlers"].get("smtp", None):
	que = queue.Queue(-1)
	queue_handler = logging.handlers.QueueHandler(que)
	smtp_handler = logging.handlers.SMTPHandler(**mdata["handlers"]["smtp"])
	listener = logging.handlers.QueueListener(que, smtp_handler)
	dlog.addHandler(queue_handler)
	listener.start()

The module imports logging, but not logging.handlers. In Python, import logging alone does not expose logging.handlers, so any mdata["handlers"]["smtp"] configuration raises AttributeError: module 'logging' has no attribute 'handlers' before the workflow starts.

Expected behavior: import logging.handlers before using QueueHandler, SMTPHandler, and QueueListener, as the generator path does implicitly/explicitly where needed.