refactor(frontend): Reactivityで型を明示するように (#12791)

* refactor(frontend): Reactivityで型を明示するように

* fix: プロパティの参照が誤っているのを修正

* fix: 初期化の値を空配列に書き換えていた部分をnullに置き換え

packages/frontend/src/widgets/WidgetInstanceCloud.vue

@@ -19,6 +19,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { shallowRef } from 'vue';
+import * as Misskey from 'misskey-js';
 import { useWidgetPropsManager, WidgetComponentEmits, WidgetComponentExpose, WidgetComponentProps } from './widget.js';
 import { GetFormResultType } from '@/scripts/form.js';
 import MkContainer from '@/components/MkContainer.vue';
@@ -48,7 +49,7 @@ const { widgetProps, configure } = useWidgetPropsManager(name,
 );
 
 const cloud = shallowRef<InstanceType<typeof MkTagCloud> | null>();
-const activeInstances = shallowRef(null);
+const activeInstances = shallowRef<Misskey.entities.FederationInstance[] | null>(null);
 
 function onInstanceClick(i) {
 	os.pageWindow(`/instance-info/${i.host}`);