fix: remove body truncation for large emails

src/email_client.py

@@ -142,8 +142,6 @@ def fetch_unseen_emails(account: EmailAccount) -> list[Email]:
             reply_to = _decode_address_header(msg.get("Reply-To", ""))
             date_str = msg.get("Date", "")
             body = _get_text_from_msg(msg)
-            if large:
-                body = body[:4000] + "\n...(邮件过长已截断)"
             body_len = len(body)
 
             logger.info("  邮件: [%s] from=%s to=%s reply-to=%s (%d 字符)", subject, sender, recipient, reply_to, body_len)