fix(config): stabilize config hook callbacks to prevent action/filter flicker

frontend/src/hooks/useJailFileConfig.ts

@@ -2,6 +2,7 @@
  * React hook for loading and updating a single parsed jail.d config file.
  */
 
+import { useCallback } from "react";
 import { useConfigItem } from "./useConfigItem";
 import { fetchParsedJailFile, updateParsedJailFile } from "../api/config";
 import type { JailFileConfig, JailFileConfigUpdate } from "../types/config";
@@ -21,12 +22,18 @@ export interface UseJailFileConfigResult {
  * @param filename - Filename including extension (e.g. ``"sshd.conf"``).
  */
 export function useJailFileConfig(filename: string): UseJailFileConfigResult {
+  const fetchFn = useCallback(() => fetchParsedJailFile(filename), [filename]);
+  const saveFn = useCallback(
+    (update: JailFileConfigUpdate) => updateParsedJailFile(filename, update),
+    [filename],
+  );
+
   const { data, loading, error, refresh, save } = useConfigItem<
     JailFileConfig,
     JailFileConfigUpdate
   >({
-    fetchFn: () => fetchParsedJailFile(filename),
-    saveFn: (update) => updateParsedJailFile(filename, update),
+    fetchFn,
+    saveFn,
     mergeOnSave: (prev, update) =>
       update.jails != null && prev
         ? { ...prev, jails: { ...prev.jails, ...update.jails } }