feat: add conversation model

app/model/ConversationModel.py

@@ -0,0 +1,13 @@
+from sqlmodel import Field
+
+from app.model.BasicModel import BasicModel
+from app.utils.create_module_service import create_model_service
+
+
+class ConversationModel(BasicModel, table=True):
+  __tablename__ = "pl_conversation"
+
+  title: str = Field(default=None, description="会话标题")
+
+
+ConversationService = create_model_service(ConversationModel)