feat(child): auto create parent-child conversations

mini-program/app/dao/child.py

@@ -26,6 +26,7 @@ class ChildDAO(BaseDAO):
         child_name: str,
         child_gender: int = 2,
         child_birthday: Optional[date] = None,
+        auto_commit: bool = True,
     ) -> int:
         result = self.db.execute(
             text(
@@ -38,7 +39,8 @@ class ChildDAO(BaseDAO):
         )
         child_id = inserted_primary_key(result)
         self._create_relation(user_id, child_id)
-        self.commit()
+        if auto_commit:
+            self.commit()
         return child_id
 
     def get_by_id(self, child_id: int) -> Optional[Mapping]: