Add functionality to restore and save test answers in localStorage for task editing; enhance user experience by preserving input across sessions.

src/pages/tasks/TaskFormPage.tsx

@@ -54,6 +54,39 @@ export const TaskFormPage: React.FC = () => {
     }
   }, [task])
 
+  // Восстановление сохранённого тестового ответа для конкретной задачи
+  useEffect(() => {
+    if (!isEdit || !id) return
+    if (typeof window === 'undefined') return
+
+    const key = `challenge-admin.task-test-answer.${id}`
+    try {
+      const saved = window.localStorage.getItem(key)
+      if (saved) {
+        setTestAnswer(saved)
+      }
+    } catch {
+      // ignore localStorage errors
+    }
+  }, [isEdit, id])
+
+  // Сохранение тестового ответа в localStorage
+  useEffect(() => {
+    if (!isEdit || !id) return
+    if (typeof window === 'undefined') return
+
+    const key = `challenge-admin.task-test-answer.${id}`
+    try {
+      if (testAnswer.trim()) {
+        window.localStorage.setItem(key, testAnswer)
+      } else {
+        window.localStorage.removeItem(key)
+      }
+    } catch {
+      // ignore localStorage errors
+    }
+  }, [isEdit, id, testAnswer])
+
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault()