Refactor app helpers and use AppStateDep in config router

Move service-dependent helper wrappers from app.utils to app.helpers and update config router activation/rollback to use explicit AppState dependency.

backend/app/services/config_file_service.py

@@ -32,6 +32,8 @@ from typing import cast
 
 import structlog
 
+from app.exceptions import FilterInvalidRegexError, JailNotFoundError
+from app.helpers.jail_helpers import reload_jails
 from app.models.config import (
     ActionConfig,
     ActionConfigUpdate,
@@ -54,9 +56,7 @@ from app.models.config import (
     JailValidationResult,
     RollbackResponse,
 )
-from app.exceptions import FilterInvalidRegexError, JailNotFoundError
 from app.utils import conffile_parser
-from app.utils.jail_utils import reload_jails
 from app.utils.fail2ban_client import (
     Fail2BanClient,
     Fail2BanConnectionError,