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/smtp_client.py

@@ -1,9 +1,12 @@
 import smtplib
+import logging
 from email.mime.text import MIMEText
 from email.mime.multipart import MIMEMultipart
 from src.config import EmailAccount
 from src.retry import retry
 
+logger = logging.getLogger(__name__)
+
 
 @retry()
 def send_reply(account: EmailAccount, to_addr: str, subject: str, body: str):
@@ -11,6 +14,7 @@ def send_reply(account: EmailAccount, to_addr: str, subject: str, body: str):
         raise RuntimeError(f"账号 {account.username} 未配置 SMTP")
 
     s = account.smtp
+    logger.info("SMTP 连接: %s:%d (ssl=%s)", s.server, s.port, s.use_ssl)
     if s.use_ssl:
         conn = smtplib.SMTP_SSL(s.server, s.port, timeout=15)
     else:
@@ -19,8 +23,10 @@ def send_reply(account: EmailAccount, to_addr: str, subject: str, body: str):
             conn.starttls()
 
     conn.login(account.username, account.password)
+    logger.info("SMTP 登录成功")
 
     reply_subject = subject if subject.lower().startswith("re:") else f"Re: {subject}"
+    logger.info("SMTP 发送: to=%s subject=%s body=%d 字符", to_addr, reply_subject, len(body))
 
     msg = MIMEMultipart("alternative")
     msg["From"] = account.username
@@ -30,3 +36,4 @@ def send_reply(account: EmailAccount, to_addr: str, subject: str, body: str):
 
     conn.sendmail(account.username, [to_addr], msg.as_string())
     conn.quit()
+    logger.info("SMTP 发送完成")