feat: init AI email summarization bot

- Multi-account IMAP email polling with UID tracking
- DeepSeek API integration with JSON Mode structured output
- Telegram notification with formatted MarkdownV2 message
- YAML config with dataclass-based type validation
- Graceful shutdown on SIGINT/SIGTERM
- 60s default polling interval

src/summarizer.py

@@ -0,0 +1,42 @@
+import logging
+from src.config import Config
+from src.email_client import fetch_unseen_emails, mark_as_seen
+from src.ai_client import summarize_email
+from src.tg_bot import send_message, format_summary
+
+logger = logging.getLogger(__name__)
+
+
+def process_all(cfg: Config):
+    for acct in cfg.email_accounts:
+        try:
+            _process_account(cfg, acct)
+        except Exception as e:
+            logger.error(f"处理邮箱 {acct.username} 时出错: {e}", exc_info=True)
+
+
+def _process_account(cfg: Config, acct):
+    logger.info(f"检查邮箱: {acct.username}")
+    emails = fetch_unseen_emails(acct)
+
+    if not emails:
+        logger.info(f"  没有新邮件")
+        return
+
+    logger.info(f"  发现 {len(emails)} 封新邮件")
+    seen_uids = []
+
+    for mail in emails:
+        try:
+            logger.info(f"  正在摘要: {mail.subject}")
+            summary = summarize_email(cfg.ai, mail.subject, mail.sender, mail.body)
+            text = format_summary(summary)
+            send_message(cfg.telegram, text)
+            seen_uids.append(mail.uid)
+            logger.info(f"  已发送到 Telegram")
+        except Exception as e:
+            logger.error(f"  处理邮件 '{mail.subject}' 失败: {e}", exc_info=True)
+            seen_uids.append(mail.uid)
+
+    if seen_uids:
+        mark_as_seen(acct, seen_uids)