refactor: Remove unused HTTPException imports from routers

After removing all try/except blocks that used HTTPException for domain
exception conversion, these imports are no longer needed in the routers.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/app/routers/action_config.py

@@ -2,16 +2,9 @@ from __future__ import annotations
 
 from typing import Annotated
 
-from fastapi import APIRouter, HTTPException, Path, Query, Request, status
+from fastapi import APIRouter, Path, Query, Request, status
 
 from app.dependencies import AuthDep, Fail2BanConfigDirDep, Fail2BanSocketDep
-from app.exceptions import (
-    ActionAlreadyExistsError,
-    ActionNameError,
-    ActionNotFoundError,
-    ActionReadonlyError,
-    ConfigWriteError,
-)
 from app.models.config import (
     ActionConfig,
     ActionCreateRequest,