fix(JlsBottomNav): 调整底栏加载失败或无数据时仅显示首页

新增getHomeOnlyTabbarItems工具方法用于获取仅包含首页的底栏项，替换所有兜底场景的默认项获取逻辑，更新README补充兜底规则说明，并补充缺失的组件类型声明

@@ -13,6 +13,10 @@ declare module '@vue/runtime-core' {
     AudioBackground1: typeof import('./src/components/audioBackground1.vue')['default']
     AudioList: typeof import('./src/components/audioList.vue')['default']
     BottomNav: typeof import('./src/components/BottomNav.vue')['default']
+    ElButton: typeof import('element-plus/es')['ElButton']
+    ElInput: typeof import('element-plus/es')['ElInput']
+    ElOption: typeof import('element-plus/es')['ElOption']
+    ElSelect: typeof import('element-plus/es')['ElSelect']
     Floor: typeof import('./src/components/Floor/index.vue')['default']
     InfoPopup: typeof import('./src/components/InfoPopup.vue')['default']
     InfoPopupLite: typeof import('./src/components/InfoPopupLite.vue')['default']
@@ -27,14 +31,19 @@ declare module '@vue/runtime-core' {
     SvgIcon: typeof import('./src/components/Floor/svgIcon.vue')['default']
     VanBackTop: typeof import('vant/es')['BackTop']
     VanButton: typeof import('vant/es')['Button']
+    VanCol: typeof import('vant/es')['Col']
     VanConfigProvider: typeof import('vant/es')['ConfigProvider']
     VanDialog: typeof import('vant/es')['Dialog']
+    VanField: typeof import('vant/es')['Field']
     VanFloatingPanel: typeof import('vant/es')['FloatingPanel']
     VanIcon: typeof import('vant/es')['Icon']
     VanImage: typeof import('vant/es')['Image']
     VanImagePreview: typeof import('vant/es')['ImagePreview']
     VanLoading: typeof import('vant/es')['Loading']
+    VanOverlay: typeof import('vant/es')['Overlay']
     VanPopup: typeof import('vant/es')['Popup']
+    VanRow: typeof import('vant/es')['Row']
+    VanSlider: typeof import('vant/es')['Slider']
     VanSwipe: typeof import('vant/es')['Swipe']
     VanSwipeItem: typeof import('vant/es')['SwipeItem']
     VanTab: typeof import('vant/es')['Tab']

@@ -9,7 +9,7 @@
 - [tabbar.api.js](/Users/huyirui/program/itomix/git/map-demo/src/components/JlsBottomNav/tabbar.api.js)
   底栏配置接口请求，当前使用 `/srv/?a=app_menu`。
 - [tabbar.utils.js](/Users/huyirui/program/itomix/git/map-demo/src/components/JlsBottomNav/tabbar.utils.js)
-  底栏数据归一化、默认项、顺序、icon class 解析、目标地址解析。
+  底栏数据归一化、首页兜底、顺序、icon class 解析、目标地址解析。
 - [useTabbar.js](/Users/huyirui/program/itomix/git/map-demo/src/components/JlsBottomNav/useTabbar.js)
   组件内状态和加载逻辑，支持 `api` / `mock` 两种加载模式。
 - [nav-state.js](/Users/huyirui/program/itomix/git/map-demo/src/components/JlsBottomNav/nav-state.js)
@@ -45,6 +45,15 @@ import JlsBottomNav from '@/components/JlsBottomNav';
 
 `visible` 为 `true` 时组件才会渲染并尝试加载数据。
 
+接口显示规则：
+
+- 只有接口成功并返回有效菜单时，才显示接口里的其他按钮
+- 如果接口返回 `data: []`
+- 如果接口失败
+- 如果接口结构异常
+
+以上情况都统一只保留 `home`
+
 ### 3. 激活态
 
 组件通过当前路由的 `activeTab` 识别高亮项，兼容以下写法：
@@ -126,6 +135,9 @@ import { getJlsTabbarPreviewOptions } from '@/components/JlsBottomNav/preview';
 ## 注意点
 
 - 组件默认按小程序 WebView 跳转方式调用 `wx.miniProgram.redirectTo / reLaunch`。
+- 底栏显示兜底规则是“只保留首页”：
+  - 只有接口成功并返回有效菜单时，才显示首页之外的其他项
+  - 接口空数组、失败、异常、无法归一化时，都只显示 `home`
 - 当前跳转逻辑是：
   - `home` 默认跳回小程序页 `/pages/index/index`
   - 其他项不会直接跳裸 H5 URL，而是优先使用接口返回的 `page_url`

@@ -111,6 +111,8 @@ export const getDefaultTabbarItem = (key) => {
 export const getDefaultTabbarItems = () =>
   TABBAR_ORDER.map((key) => getDefaultTabbarItem(key)).filter(Boolean);
 
+export const getHomeOnlyTabbarItems = () => [getDefaultTabbarItem('home')].filter(Boolean);
+
 const buildTabbarPageUrl = (key, webviewUrl, webviewTitle, rawPageUrl = '') => {
   if (key === 'home') {
     return rawPageUrl || '/pages/index/index';
@@ -224,12 +226,12 @@ const normalizeTabbarObjectItems = (rawMap = {}) => {
 
 export const normalizeTabbarItems = (rawItems = []) => {
   if (!Array.isArray(rawItems) || !rawItems.length) {
-    return getDefaultTabbarItems();
+    return getHomeOnlyTabbarItems();
   }
 
   const normalizedItems = rawItems.map((item) => normalizeTabbarItem(item)).filter(Boolean);
 
-  return normalizedItems.length ? normalizedItems : getDefaultTabbarItems();
+  return normalizedItems.length ? normalizedItems : getHomeOnlyTabbarItems();
 };
 
 export const normalizeTabbarPayload = (rawPayload = null) => {
@@ -245,7 +247,7 @@ export const normalizeTabbarPayload = (rawPayload = null) => {
   const objectPayload = rawPayload?.tab_items || rawPayload?.tabs || rawPayload?.menus || rawPayload;
   const normalizedItems = normalizeTabbarObjectItems(objectPayload);
 
-  return normalizedItems.length ? normalizedItems : getDefaultTabbarItems();
+  return normalizedItems.length ? normalizedItems : getHomeOnlyTabbarItems();
 };
 
 export const resolveTabbarTargetUrl = (item = {}) => {

@@ -2,14 +2,14 @@ import { computed, reactive, readonly } from 'vue';
 import { getTabbarConfigAPI } from './tabbar.api';
 import {
   getDefaultTabbarItem,
-  getDefaultTabbarItems,
+  getHomeOnlyTabbarItems,
   normalizeTabbarKey,
   normalizeTabbarPayload,
   resolveTabbarTargetUrl,
 } from './tabbar.utils';
 
 const state = reactive({
-  tabItems: getDefaultTabbarItems(),
+  tabItems: getHomeOnlyTabbarItems(),
   loaded: false,
   loading: false,
   loadMode: 'api',
@@ -18,7 +18,7 @@ const state = reactive({
 let tabbarRequestPromise = null;
 
 const applyFallbackItems = () => {
-  state.tabItems = getDefaultTabbarItems();
+  state.tabItems = getHomeOnlyTabbarItems();
 };
 
 const resolveLoadMode = (options = {}) => (options.useMock ? 'mock' : 'api');