debug: add skip_uids logging to diagnose re-fetch issue

src/email_client.py

@@ -113,6 +113,7 @@ def fetch_unseen_emails(account: EmailAccount, skip_uids: set[bytes] | None = No
     conn = _login_and_prepare(account, select_inbox=False)
     if skip_uids is None:
         skip_uids = set()
+    logger.info("fetch_unseen_emails: %s, skip_uids大小=%d", account.username, len(skip_uids))
 
     # 列出所有文件夹
     _, folder_data = conn.list()
@@ -147,7 +148,11 @@ def fetch_unseen_emails(account: EmailAccount, skip_uids: set[bytes] | None = No
             skipped += len(uids) - len(new_uids)
             if not new_uids:
                 continue
-            logger.info("  %s: %d 封未读 (%d 封跳过)", folder, len(new_uids), len(uids) - len(new_uids))
+            if skipped > 0 or len(uids) > 0:
+                logger.info("  %s: %d 封未读 (%d 封跳过) skip_uids=%d",
+                            folder, len(new_uids), len(uids) - len(new_uids), len(skip_uids))
+                if skip_uids and len(skip_uids) <= 5:
+                    logger.info("    skip_uids 内容: %s", [u for u in skip_uids])
 
             for uid in new_uids:
                 try: