Feature/memory work (#68)

* feat(memory): add conversation title to conversation list response for frontend display

* feat(memory): optimize conversation retrieval, enable working memory to return conversation question summaries

* fix(memory): fix conversation re-generation logic

* style(desc): improve description of get_conversation function

api/app/models/conversation_model.py

@@ -65,9 +65,9 @@ class ConversationDetail(Base):
     conversation_id = Column(UUID(as_uuid=True), ForeignKey("conversations.id"))
 
     theme = Column(String, comment="会话主题")
-    theme_intro = Column(String, comment="主题介绍")
     summary = Column(String, comment="会话摘要")
     takeaways = Column(JSON, comment="会话要点")
+    question = Column(JSON, comment="用户问题")
     info_score = Column(Integer, comment="会话信息量评分")