chore: retire demo technical debt

backend/app/api/profiles.py

@@ -4,7 +4,7 @@ from datetime import date
 from typing import Literal
 
 from fastapi import APIRouter, Depends, HTTPException, status
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -42,6 +42,8 @@ class ChildProfileUpdate(BaseModel):
 class ChildProfileResponse(BaseModel):
     """Profile response."""
 
+    model_config = ConfigDict(from_attributes=True)
+
     id: str
     name: str
     avatar_url: str | None
@@ -53,9 +55,6 @@ class ChildProfileResponse(BaseModel):
     stories_count: int
     total_reading_time: int
 
-    class Config:
-        from_attributes = True
-
 
 class ChildProfileListResponse(BaseModel):
     """Profile list response."""