## 27) Error response body shape is inconsistent

backend/app/routers/history.py

@@ -17,7 +17,7 @@ from __future__ import annotations
 
 from typing import Literal
 
-from fastapi import APIRouter, HTTPException, Query, Request
+from fastapi import APIRouter, Query, Request
 
 from app.dependencies import (
     AuthDep,
@@ -26,6 +26,7 @@ from app.dependencies import (
     HistoryServiceContextDep,
     HttpSessionDep,
 )
+from app.exceptions import HistoryNotFoundError
 from app.models.ban import BanOrigin, TimeRange
 from app.models.history import HistoryListResponse, IpDetailResponse
 from app.services import history_service
@@ -188,6 +189,6 @@ async def get_ip_history(
     )
 
     if detail is None:
-        raise HTTPException(status_code=404, detail=f"No history found for IP {ip!r}.")
+        raise HistoryNotFoundError(ip)
 
     return detail