feat(frontend): セーフモード (#16245)

* feat(frontend): セーフモード

* Update Changelog

* Update Changelog

* fix

* fix

* Update Changelog

* Update Changelog

* PWAのショートカット経由でもセーフモードで起動できるように

* Update ClientServerService.ts

---------

Co-authored-by: syuilo <4439005+syuilo@users.noreply.github.com>

packages/frontend/src/pages/settings/theme.vue

@@ -35,7 +35,9 @@ SPDX-License-Identifier: AGPL-3.0-only
 			</div>
 		</div>
 
-		<div class="_gaps">
+		<MkInfo v-if="isSafeMode" warn>{{ i18n.ts.themeIsDefaultBecauseSafeMode }}</MkInfo>
+
+		<div v-else class="_gaps">
 			<template v-if="!store.r.darkMode.value">
 				<SearchMarker :keywords="['light', 'theme']">
 					<MkFolder :defaultOpen="true" :max-height="500">
@@ -204,12 +206,14 @@ import JSON5 from 'json5';
 import defaultLightTheme from '@@/themes/l-light.json5';
 import defaultDarkTheme from '@@/themes/d-green-lime.json5';
 import type { Theme } from '@/theme.js';
+import { isSafeMode } from '@@/js/config.js';
 import * as os from '@/os.js';
 import MkSwitch from '@/components/MkSwitch.vue';
 import FormSection from '@/components/form/section.vue';
 import FormLink from '@/components/form/link.vue';
 import MkFolder from '@/components/MkFolder.vue';
 import MkThemePreview from '@/components/MkThemePreview.vue';
+import MkInfo from '@/components/MkInfo.vue';
 import { getBuiltinThemesRef, getThemesRef, removeTheme } from '@/theme.js';
 import { isDeviceDarkmode } from '@/utility/is-device-darkmode.js';
 import { store } from '@/store.js';