refactor: split AI processor and TG worker into separate threads

- Three independent threads: email poller, AI processor, TG worker
- Two queues: _email_queue (raw emails→AI), _tg_queue (AI results→TG)
- summarizer.py split: ai_process() (AI only) + tg_send_and_mark() (TG only)
- AI retries no longer affect TG polling or email polling

src/summarizer.py

@@ -1,5 +1,5 @@
 import logging
-from typing import Generator
+from typing import Generator, Optional
 from src.config import Config
 from src.email_client import fetch_unseen_emails, mark_as_seen, Email
 from src.ai_client import summarize_email
@@ -21,12 +21,25 @@ def poll_accounts(cfg: Config) -> Generator[tuple[int, Email], None, None]:
             logger.error(f"轮询 {acct.username} 失败: {e}", exc_info=True)
 
 
-def process_email(cfg: Config, acct_idx: int, mail: Email):
+def ai_process(cfg: Config, acct_idx: int, mail: Email) -> Optional[dict]:
     acct = cfg.email_accounts[acct_idx]
     logger.info(f"  正在摘要: {mail.subject}")
     summary = summarize_email(cfg.ai, acct.username, mail.subject, mail.sender, mail.body)
     summary["recipient"] = acct.username
     text = format_summary(summary)
-    send_summary(cfg.telegram, cfg.telegram.chat_id, text, summary, mail.body, acct_idx)
-    mark_as_seen(acct, [mail.uid])
-    logger.info(f"  已处理: {mail.subject}")
+    return {
+        "text": text,
+        "data": summary,
+        "original_body": mail.body,
+        "acct_idx": acct_idx,
+        "uid": mail.uid,
+    }
+
+
+def tg_send_and_mark(cfg: Config, info: dict):
+    acct = cfg.email_accounts[info["acct_idx"]]
+    send_summary(cfg.telegram, cfg.telegram.chat_id,
+                 info["text"], info["data"],
+                 info["original_body"], info["acct_idx"])
+    mark_as_seen(acct, [info["uid"]])
+    logger.info(f"  已发送并标记已读")