feat(server): add PUT /attachment/config with removal guard

Co-Authored-By: Claude <noreply@anthropic.com>

app/api/v1/attachment.py

@@ -3,8 +3,15 @@ from sqlalchemy.orm import Session
 
 from app.core.database import get_db
 from app.models.attachment import AttachmentCategory
-from app.schemas.attachment import AttachmentStatusResponse, CategoryResponse
-from app.services.attachment_service import get_attachment_status
+from app.schemas.attachment import (
+    AttachmentConfigRequest,
+    AttachmentStatusResponse,
+    CategoryResponse,
+)
+from app.services.attachment_service import (
+    configure_attachment,
+    get_attachment_status,
+)
 
 router = APIRouter(tags=["attachment"])
 
@@ -26,3 +33,8 @@ def list_categories(db: Session = Depends(get_db)):
 @router.get("/attachment/status", response_model=AttachmentStatusResponse)
 def attachment_status(zongpai_no: str, db: Session = Depends(get_db)):
     return get_attachment_status(db, zongpai_no)
+
+
+@router.put("/attachment/config", response_model=AttachmentStatusResponse)
+def put_attachment_config(req: AttachmentConfigRequest, db: Session = Depends(get_db)):
+    return configure_attachment(db, req)