fix: skip already-processing UIDs at FETCH level to avoid downloading email content

src/summarizer.py

@@ -8,11 +8,11 @@ from src.tg_bot import send_summary, send_thinking, edit_message, format_summary
 logger = logging.getLogger(__name__)
 
 
-def poll_accounts(cfg: Config) -> Generator[tuple[int, Email], None, None]:
+def poll_accounts(cfg: Config, skip_uids: set[bytes] | None = None) -> Generator[tuple[int, Email], None, None]:
     for idx, acct in enumerate(cfg.email_accounts):
         try:
             logger.info(f"检查邮箱: {acct.username}")
-            emails = fetch_unseen_emails(acct)
+            emails = fetch_unseen_emails(acct, skip_uids=skip_uids)
             if emails:
                 logger.info(f"  发现 {len(emails)} 封新邮件")
             for mail in emails: