fix: use Response class for 204 DELETE routes

FastAPI latest rejects 204 with response body.
Use response_class=Response and return Response(status_code=204).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/services/chart-service/src/infrastructure/api/routes.py

@@ -4,6 +4,7 @@ import uuid
 from typing import Any
 
 from fastapi import APIRouter, Depends, HTTPException
+from starlette.responses import Response
 
 from shared.exceptions import EntityNotFoundError
 
@@ -74,15 +75,16 @@ async def update_chart(
         raise HTTPException(status_code=422, detail=str(exc))
 
 
-@router.delete("/{chart_id}", status_code=204)
+@router.delete("/{chart_id}", status_code=204, response_class=Response)
 async def delete_chart(
     chart_id: uuid.UUID,
     repository: ChartRepository = Depends(get_chart_repository),
-) -> None:
+) -> Response:
     chart = await repository.find_by_id(chart_id)
     if chart is None:
         raise HTTPException(status_code=404, detail="Chart not found")
     await repository.delete(chart_id)
+    return Response(status_code=204)
 
 
 @router.get("/{chart_id}/option", response_model=EChartsOptionResponse)

backend/services/data-service/src/infrastructure/api/routes.py

@@ -4,6 +4,7 @@ import uuid
 from typing import Any
 
 from fastapi import APIRouter, Depends, HTTPException, UploadFile, File, Query
+from starlette.responses import Response
 
 from shared.exceptions import EntityNotFoundError, FileParsingError
 
@@ -93,15 +94,16 @@ async def update_row(
     return {"row_index": row_index, "row": dataset.raw_data[row_index]}
 
 
-@router.delete("/{dataset_id}", status_code=204)
+@router.delete("/{dataset_id}", status_code=204, response_class=Response)
 async def delete_dataset(
     dataset_id: uuid.UUID,
     use_case: DeleteDataSetUseCase = Depends(get_delete_dataset_usecase),
-) -> None:
+) -> Response:
     try:
         await use_case.execute(dataset_id)
     except EntityNotFoundError:
         raise HTTPException(status_code=404, detail="DataSet not found")
+    return Response(status_code=204)
 
 
 @router.get("/{dataset_id}/structure")

backend/services/template-service/src/infrastructure/api/routes.py

@@ -4,6 +4,7 @@ import uuid
 from typing import Any, Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Query
+from starlette.responses import Response
 
 from shared.exceptions import EntityNotFoundError, ValidationError
 from shared.types import TemplateType
@@ -120,15 +121,16 @@ async def update_template(
         raise HTTPException(status_code=422, detail=str(e))
 
 
-@router.delete("/{template_id}", status_code=204)
+@router.delete("/{template_id}", status_code=204, response_class=Response)
 async def delete_template(
     template_id: uuid.UUID,
     usecase: DeleteTemplateUseCase = Depends(get_delete_template_usecase),
-) -> None:
+) -> Response:
     try:
         await usecase.execute(template_id)
     except EntityNotFoundError as e:
         raise HTTPException(status_code=404, detail=str(e))
+    return Response(status_code=204)
 
 
 @router.post("/import", status_code=201)