feat(header): 搜索框改居中命令面板，应用列表数据与 loading 与 AppList 共享

- header.scss: 删旧 .search-box 与 fade1/search-animation/icon-animation 动画段，
  新增 app-cmdk-* 面板样式。样式段必须放顶层——面板 Teleport 到 body，嵌进
  .default-header 会生成后代选择器而匹配不到
- Header.vue: 搜索 li 收敛为单图标 + openSearch；模板末尾追加 <Teleport to="body">
  命令面板，支持实时过滤 / ↑↓ 键盘导航 / Enter 打开 / Esc 关闭 / 空结果态；
  删 watch(isSearching) 与空函数 showSeachBox；挂/卸 window keydown
- store/index.ts: 新增 appListLoading 字段与 setAppListLoading
- utils/bschLinkPage.ts: 抽出 openAppPage(app, ifameAppIdArr)，与点击应用图标同一路径
- AppList.vue: reloadAppData 写 store（数据 + loading，try/finally）；
  linkPage(item) 委托 openAppPage

硬约束保持不动：watch(searchAppText) -> mittBus.emit("searchChange")（背景应用网格靠它过滤）、
isSearchIconShow（route.name === "apps"）。

src/components/Header.vue

@@ -8,17 +8,9 @@
                 </div>
             </li>
             <li v-if="isSearchIconShow">
-                <Transition name="fade1" :duration="{ enter: 1000, leave: 0 }">
-                    <div v-show="!isSearching" @click="isSearching = true" class="icon-box" v-wave>
-                        <SvgIcon name="header-1" color="#333333" />
-                    </div>
-                </Transition>
-                <Transition name="search" :duration="{ enter: 300, leave: 300 }">
-                    <div v-show="isSearching" class="search-box">
-                        <input ref="refSearchInput" v-model="searchAppText" type="text" placeholder="请输入应用名称搜索" />
-                        <SvgIcon @click="isSearching = false" class="icon" name="header-1" size="20" color="#c4c4c4" />
-                    </div>
-                </Transition>
+                <div class="icon-box" v-wave @click="openSearch">
+                    <SvgIcon name="header-1" color="#333333" />
+                </div>
             </li>
             <!-- 人像图标 =唯一入口（2026-10-08整合）：铃铛与齿轮两枚图标下线，
                  消息中心仍走左侧菜单 /msg（LeftMenu 保留未读角标）；
@@ -180,13 +172,60 @@
 
     <StatsBarModal ref="refStatsBarModal" />
     <TeacherCopilotModal ref="refTeacherCopilotModal" />
+
+    <!-- 搜索命令面板（2026-10-08 定稿 B 方案）：必须 Teleport 到 body ——
+         .default-header 有 position:relative + z-index:10，会创建层叠上下文，
+         面板写在 Header 内部时无论 z-index 多高，对外只表现为 10，会被左侧菜单与内容区盖住 -->
+    <Teleport to="body">
+        <div class="app-cmdk-layer" :class="{ 'is-open': isSearching }">
+            <div class="app-cmdk-mask" @click="closeSearch"></div>
+            <div class="app-cmdk-panel">
+                <div class="app-cmdk-hd">
+                    <SvgIcon name="header-1" size="19" color="#98a2b0" />
+                    <input
+                        ref="refSearchInput"
+                        v-model="searchAppText"
+                        type="text"
+                        placeholder="输入应用名以搜索"
+                        autocomplete="off"
+                    />
+                    <span class="app-cmdk-kbd">Esc</span>
+                </div>
+                <div class="app-cmdk-list" :class="{ 'is-instant': !cmdkStagger }" ref="refCmdkList">
+                    <div
+                        v-for="(item, i) in cmdkResult"
+                        :key="item.id ?? i"
+                        class="app-cmdk-item"
+                        :class="{ 'is-hl': i === cmdkIndex }"
+                        :style="{ '--i': i }"
+                        @click="pickApp(item)"
+                    >
+                        <AppIcon
+                            v-if="vectorIconOf(item)"
+                            :name="vectorIconOf(item)"
+                            scene="tile"
+                            :tint="item.iconColor"
+                        />
+                        <img v-else :src="$utils.appIconPath(item.icon)" class="app-cmdk-img" alt="" />
+                        <span class="app-cmdk-name">{{ item.name }}</span>
+                    </div>
+                </div>
+                <div class="app-cmdk-empty" :class="{ 'is-show': !cmdkResult.length }">
+                    {{ store.appListLoading ? "正在加载应用…" : "未找到匹配的应用" }}
+                </div>
+                <div class="app-cmdk-ft">
+                    <span>↑↓ 选择</span><span>↵ 打开</span><span>Esc 关闭</span>
+                </div>
+            </div>
+        </div>
+    </Teleport>
 </template>
 
 <script lang="ts" setup>
 import useCurrentInstance from "@/utils/hook/useCurrentInstance";
 import SvgIcon from "@/components/SvgIcon.vue";
 import vuescroll from "vuescroll";
-import { ref, reactive, computed, onMounted, onUnmounted, inject, watch } from "vue";
+import { ref, reactive, computed, onMounted, onUnmounted, inject, watch, nextTick } from "vue";
 import { useDefaultStore } from "@/store";
 import { useRoute, useRouter } from "vue-router";
 import { requireImg } from "@/utils/hook/useImg";
@@ -202,6 +241,9 @@ import UserSettingApi from "@/api/UserSettingApi";
 import mittBus from "@/utils/mitt";
 import MenuBarApi from "@/api/MenuBarApi";
 import Utils from "@/utils";
+import AppIcon from "@/components/AppIcon.vue";
+import { appiconKeyOf } from "@/constants/appIconRules";
+import { openAppPage } from "@/utils/bschLinkPage";
 
 const route = useRoute();
 const router = useRouter();
@@ -360,22 +402,88 @@ onMounted(async () => {
         isSearching.value = false;
         searchAppText.value = null;
     });
+    window.addEventListener("keydown", onCmdkKeydown);
 });
 onUnmounted(() => {
     mittBus.off("searchReset");
+    window.removeEventListener("keydown", onCmdkKeydown);
     closeMsgWs();
 });
-watch(isSearching, val => {
-    if (val) {
-        setTimeout(() => refSearchInput.value?.focus(), 300);
-    } else {
-        // searchAppText.value = null;
-    }
-});
-
 watch(searchAppText, val => {
+    cmdkStagger.value = false; // 输入过滤时不重播逐条入场
     mittBus.emit("searchChange", val);
 });
+// ===== 搜索命令面板（2026-10-08 定稿 B 方案）=====
+const refCmdkList = ref<any>();
+const cmdkIndex = ref(0);
+const cmdkStagger = ref(true); // 仅首次打开做逐条入场，输入过滤时不重播
+
+/** 与 AppList.vue / index.vue / SearchPanel.vue 同口径的矢量渲染回退链 */
+function vectorIconOf(item: any): string {
+    if (item?.iconKey) return item.iconKey;
+    if (item?.icon) return "";
+    return appiconKeyOf(item?.name || "");
+}
+
+/** 结果取自 store（由 AppList.reloadAppData 写入），与背景应用网格同源同口径 */
+const cmdkResult = computed(() => {
+    const all = store.getFlattenAppList;
+    const q = (searchAppText.value || "").trim();
+    if (!q) return all;
+    return all.filter((x: any) => x.name.indexOf(q) !== -1);
+});
+
+function openSearch() {
+    cmdkStagger.value = true;
+    cmdkIndex.value = 0;
+    searchAppText.value = null;
+    isSearching.value = true;
+    nextTick(() => refSearchInput.value?.focus());
+}
+
+function closeSearch() {
+    isSearching.value = false;
+    searchAppText.value = null;
+}
+
+function moveHighlight(step: number) {
+    const len = cmdkResult.value.length;
+    if (!len) return;
+    cmdkIndex.value = (cmdkIndex.value + step + len) % len;
+    nextTick(() => {
+        const el = refCmdkList.value?.children?.[cmdkIndex.value];
+        el?.scrollIntoView({ block: "nearest" });
+    });
+}
+
+function pickApp(item: any) {
+    closeSearch();
+    openAppPage(item, $conf.ifameAppIdArr); // 与点击应用图标同一条路径
+}
+
+function onCmdkKeydown(ev: KeyboardEvent) {
+    if (!isSearching.value) return; // 面板未开：绝不拦截全局按键
+    if (ev.key === "Escape") {
+        closeSearch();
+        return;
+    }
+    if (ev.key === "ArrowDown") {
+        ev.preventDefault();
+        moveHighlight(1);
+        return;
+    }
+    if (ev.key === "ArrowUp") {
+        ev.preventDefault();
+        moveHighlight(-1);
+        return;
+    }
+    if (ev.key === "Enter") {
+        ev.preventDefault();
+        const it = cmdkResult.value[cmdkIndex.value];
+        if (it) pickApp(it);
+    }
+}
+
 function getIsCheckRoles(item: RoleInfo) {
     return isEqual(item, store.curRoleInfo);
 }
@@ -487,8 +595,6 @@ async function linkLogoSetting() {
     isLogoShow.value = true;
 }
 
-function showSeachBox() { }
-
 /** 卡片菜单：个人信息 → 设置中心 profile pane（与通知端/用户中心同一地址）。
  *  注意：mittBus 的 showUserInfoModal 事件仍由 AppHeader/BschIframe 使用，此处不再触发 */
 function showUserInfo() {