fix: 皮肤站内嵌 iframe 显式委派 clipboard-write/read 权限，修复无法复制

apps/app-frontend/src/components/ui/SkinSiteFrame.vue

@@ -16,6 +16,7 @@ const messages = defineMessages({
 <template>
 	<iframe
 		:src="skinSiteFrameUrl"
+		allow="clipboard-write; clipboard-read"
 		:title="formatMessage(messages.frameTitle)"
 		class="block h-full min-h-0 w-full border-0"
 	/>