ask-fastapi-architect

<critical_constraints> ❌ NO global DB sessions → use Depends(get_db) ❌ NO manually instantiating services in routes → use Depends ❌ NO routes without response_model → prevents data leaks ✅ MUST use Pydantic V2 (model_config, ConfigDict) ✅ MUST use AsyncSession with select() ✅ MUST use alembic for migrations </critical_constraints>