fix(captain): 护栏/回复指南编辑按钮不生效

根因：
1. guardrails/guidelines 页面直接导航时 store 无助手记录，getRecord
   返回空对象导致列表为空、编辑无数据
2. storeFactoryHelper updateRecord 用 EDIT mutation（仅更新已有记录），
   store 为空时 API 返回数据被丢弃

修复：
- storeFactoryHelper: updateRecord 改用 UPSERT，确保 API 返回记录始终写入 store
- guardrails/Index.vue & guidelines/Index.vue: onMounted 时若 store 无记录
  则 dispatch captainAssistants/show 拉取单条助手数据

frontend/app/javascript/dashboard/routes/dashboard/captain/assistants/guardrails/Index.vue

@@ -1,5 +1,5 @@
 <script setup>
-import { computed, ref } from 'vue';
+import { computed, ref, onMounted } from 'vue';
 import { useRoute } from 'vue-router';
 import { useI18n } from 'vue-i18n';
 import { useAlert } from 'dashboard/composables';
@@ -30,6 +30,14 @@ const assistant = computed(() =>
   store.getters['captainAssistants/getRecord'](assistantId.value)
 );
 
+// Fetch the assistant record if it's not already in the store
+// (e.g. when navigating directly to this page via URL)
+onMounted(() => {
+  if (!assistant.value?.id) {
+    store.dispatch('captainAssistants/show', assistantId.value);
+  }
+});
+
 const searchQuery = ref('');
 const newInlineRule = ref('');
 const newDialogRule = ref('');

frontend/app/javascript/dashboard/routes/dashboard/captain/assistants/guidelines/Index.vue

@@ -1,5 +1,5 @@
 <script setup>
-import { computed, ref } from 'vue';
+import { computed, ref, onMounted } from 'vue';
 import { useRoute } from 'vue-router';
 import { useI18n } from 'vue-i18n';
 import { useAlert } from 'dashboard/composables';
@@ -30,6 +30,14 @@ const assistant = computed(() =>
   store.getters['captainAssistants/getRecord'](assistantId.value)
 );
 
+// Fetch the assistant record if it's not already in the store
+// (e.g. when navigating directly to this page via URL)
+onMounted(() => {
+  if (!assistant.value?.id) {
+    store.dispatch('captainAssistants/show', assistantId.value);
+  }
+});
+
 const searchQuery = ref('');
 const newInlineRule = ref('');
 const newDialogRule = ref('');

frontend/app/javascript/dashboard/store/storeFactoryHelper.js

@@ -56,7 +56,10 @@ export const updateRecord =
     commit(mutationTypes.SET_UI_FLAG, { updatingItem: true });
     try {
       const response = await API.update(id, updateObj);
-      commit(mutationTypes.EDIT, response.data);
+      // Use UPSERT instead of EDIT so that the record is added to the store
+      // even if it wasn't previously loaded (e.g. direct URL navigation to
+      // a sub-page like guardrails/guidelines without visiting the list page).
+      commit(mutationTypes.UPSERT, response.data);
       return response.data;
     } catch (error) {
       return throwErrorMessage(error);