外观偏好异步补齐C：接 A 类主题通道 loader + 顶栏云海 logo 徽标 + 平台键 yh-logo-url

- index.html env-config 引导后插入 A 类免插件 loader（svc-hall cf11ef8 样板：staticHost > baseHost > %VITE_THEME_HOST% 仅 dev > 同源 /static，document.write parser-blocking，纯叠加）
- vite.config 补 /static dev 代理（YH_THEME_PROXY_TARGET 可覆盖，默认线上通道）
- header-container 首位插入 .logo-badge（结构与 Notice 对齐，皮肤由通道 base.layout.css 提供）；拷贝平台 yunhai-logo.svg 资产兜底
- localStorage["yh-logo-url"] 优先，@error 回落兜底；mounted 读一次 + 监听 yh-appearance-updated 即时切换

src/components/layout.vue

@@ -1,13 +1,35 @@
 <script setup lang="ts">
-import { ref, onBeforeMount, watch, computed } from "vue";
+import { ref, onBeforeMount, onBeforeUnmount, onMounted, watch, computed } from "vue";
 import { useRoute, useRouter } from "vue-router";
 import { Message } from "view-ui-plus";
 import { resolveMenuPage } from "@/utils/menuRoute";
+import defaultLogo from "@/assets/image/yunhai-logo.svg";
 
 const props = defineProps<{ layoutData: Record<string, any> }>();
 const route = useRoute();
 const router = useRouter();
 
+// 顶栏 Logo：localStorage["yh-logo-url"]（平台键，yh-theme-init 异步补齐段写入）优先，本仓资产兜底——绝无空 src/裂图。
+// 刷新：mounted 读一次 + 监听 yh-appearance-updated（服务端偏好到达后即时切换，无需刷新页面）。
+const logoUrl = ref<string>(defaultLogo);
+const readLogoUrl = () => {
+    let v: string | null = null;
+    try {
+        v = localStorage.getItem("yh-logo-url");
+    } catch {
+        v = null;
+    }
+    logoUrl.value = v || defaultLogo;
+};
+const onLogoError = () => {
+    if (logoUrl.value !== defaultLogo) logoUrl.value = defaultLogo;
+};
+onMounted(() => {
+    readLogoUrl();
+    document.addEventListener("yh-appearance-updated", readLogoUrl);
+});
+onBeforeUnmount(() => document.removeEventListener("yh-appearance-updated", readLogoUrl));
+
 const isPanel = ref(false);
 const currPath = ref<string>("");
 const navPath = ref<any[]>([]);
@@ -166,6 +188,8 @@ function linkHomePage() {
 <template>
     <div class="layout-wrap">
         <header class="header-container fix">
+            <!-- 云海 logo 徽标（结构与 Notice layout 对齐，皮肤见通道 base.layout.css .logo-badge） -->
+            <span class="logo-badge fl"><img :src="logoUrl" alt="云海" @error="onLogoError" /></span>
             <div class="fl align-middle icon-box">
                 <div title="首页" class="icon-btn" @click="linkHomePage">
                     <i class="iconfont icon-shouye"></i>