解决超话签到中选择性签到的逻辑问题

backend/shared/models/account.py

@@ -2,7 +2,7 @@
 
 import uuid
 
-from sqlalchemy import Column, DateTime, ForeignKey, String, Text
+from sqlalchemy import Column, DateTime, ForeignKey, JSON, String, Text
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql import func
 
@@ -19,6 +19,7 @@ class Account(Base):
     encrypted_cookies = Column(Text, nullable=False)
     iv = Column(String(32), nullable=False)
     status = Column(String(20), default="pending")
+    selected_topics = Column(JSON, nullable=True)  # 用户选择的签到超话列表，null=全部
     last_checked_at = Column(DateTime, nullable=True)
     created_at = Column(DateTime, server_default=func.now())