fix(frontend): classic uiが表示できない

Fix #15715

packages/frontend/src/ui/classic.vue

@@ -16,8 +16,9 @@ SPDX-License-Identifier: AGPL-3.0-only
 		</div>
 
 		<main class="main" @contextmenu.stop="onContextmenu">
-			<div class="content" style="container-type: inline-size;">
-				<RouterView/>
+			<div class="content">
+				<StackingRouterView v-if="prefer.s['experimental.stackingRouterView']"/>
+				<RouterView v-else/>
 			</div>
 		</main>
 
@@ -318,4 +319,8 @@ onMounted(() => {
 		pointer-events: none;
 	}
 }
+
+.content {
+	height: 100%;
+}
 </style>