fix: use threading.Event for immediate shutdown instead of sleep loops

main.py

@@ -28,6 +28,7 @@ _log_listener.start()
 logger = logging.getLogger("main")
 
 _running = True
+_shutdown_event = threading.Event()
 _pending_lock = threading.Lock()
 _pending_uids: set[bytes] = set()
 _processing_uids: set[bytes] = set()  # 正在处理（含等待TG发送）的邮件UID
@@ -42,6 +43,7 @@ def _signal_handler(signum, frame):
     global _running
     logger.info("收到退出信号，正在停止...")
     _running = False
+    _shutdown_event.set()
 
 
 def _email_poller(cfg):
@@ -65,10 +67,7 @@ def _email_poller(cfg):
             logger.error(f"邮件轮询线程异常: {e}", exc_info=True)
             time.sleep(5)
         if _running:
-            for _ in range(cfg.polling.interval_seconds):
-                if not _running:
-                    return
-                time.sleep(1)
+            _shutdown_event.wait(cfg.polling.interval_seconds)
 
 
 def _ai_processor(cfg):
@@ -129,7 +128,7 @@ def _tg_worker(cfg):
                     pass
 
         if _running:
-            time.sleep(1)
+            _shutdown_event.wait(1)
 
 
 def main():
@@ -158,9 +157,10 @@ def main():
             if tick % 30 == 0:
                 logger.info("队列状态: email_queue=%d tg_queue=%d pending_uids=%d",
                             _email_queue.qsize(), _tg_queue.qsize(), len(_pending_uids))
-            time.sleep(1)
+            _shutdown_event.wait(1)
     except KeyboardInterrupt:
         _running = False
+        _shutdown_event.set()
 
     for t in threads:
         t.join(timeout=5)