feat: enhance logging detail across all modules

- email_client: log IMAP connection, login, UNSEEN count, each email
  details (subject/sender/body size), mark-as-seen progress
- ai_client: log AI request params, timing, token usage, response size
- smtp_client: log SMTP connect, login, send details
- tg_bot: log all callback actions with subject context, message states
- main: periodic queue depth report (email_queue/tg_queue/pending_uids)

src/email_client.py

@@ -1,11 +1,14 @@
 import imaplib
 import email
+import logging
 from email.header import decode_header
 from email.utils import parsedate_to_datetime
 from typing import Optional
 from src.config import EmailAccount
 from src.retry import retry
 
+logger = logging.getLogger(__name__)
+
 
 class Email:
     def __init__(self, uid: bytes, subject: str, sender: str, body: str, date: str):
@@ -69,11 +72,15 @@ def _select_mailbox(conn, mailbox: str = "INBOX"):
 
 
 def _login_and_prepare(account: EmailAccount):
+    logger.info("连接 %s:%d", account.imap_server, account.imap_port)
     conn = imaplib.IMAP4_SSL(account.imap_server, account.imap_port)
     conn.login(account.username, account.password)
+    logger.info("登录成功: %s", account.username)
     if _check_provider(account.username, _PROVIDERS_NEED_ID):
+        logger.info("发送 ID 命令 (126/163 兼容)")
         _send_id_command(conn)
     _select_mailbox(conn)
+    logger.info("已选择 INBOX")
     return conn
 
 
@@ -83,11 +90,13 @@ def fetch_unseen_emails(account: EmailAccount) -> list[Email]:
 
     _, data = conn.uid("SEARCH", None, "UNSEEN")
     uids = data[0].split() if data[0] else []
+    logger.info("UNSEEN 数量: %d", len(uids))
     emails = []
 
     for uid in uids:
         _, msg_data = conn.uid("FETCH", uid, "RFC822")
         if msg_data[0] is None:
+            logger.warning("UID %s FETCH 返回空，跳过", uid)
             continue
         raw_email = msg_data[0][1]
         msg = email.message_from_bytes(raw_email)
@@ -96,10 +105,13 @@ def fetch_unseen_emails(account: EmailAccount) -> list[Email]:
         sender = _decode_str(msg.get("From", ""))
         date_str = msg.get("Date", "")
         body = _get_text_from_msg(msg)
+        body_len = len(body)
 
+        logger.info("  邮件: [%s] %s <%s> (%d 字符)", subject, sender, date_str, body_len)
         emails.append(Email(uid=uid, subject=subject, sender=sender, body=body, date=date_str))
 
     conn.logout()
+    logger.info("共获取 %d 封新邮件", len(emails))
     return emails
 
 
@@ -107,7 +119,9 @@ def fetch_unseen_emails(account: EmailAccount) -> list[Email]:
 def mark_as_seen(account: EmailAccount, uids: list[bytes]):
     if not uids:
         return
+    logger.info("标记 %d 封邮件为已读", len(uids))
     conn = _login_and_prepare(account)
     for uid in uids:
         conn.uid("STORE", uid, "+FLAGS", "\\Seen")
     conn.logout()
+    logger.info("标记完成")