feat(tab): 小程序仅保留 3 个 tab：预约/测评/入驻

- app.config tabBar.list 减为 booking(预约)/test(测评)/park-apply(入驻)，首页/资讯/我的移出 tab（保留为可导航页）
- custom-tab-bar LIST 同步 3 项、去居中首页 blob；selected 默认 0(预约)
- park-apply 加 useTabIndex(2) 成为 tab；首页「申请入驻」entry 改 switchTab
- 引导页改 booking(预约) 为启动 tab

Co-Authored-By: Claude <noreply@anthropic.com>

miniprogram/src/app.config.js

@@ -1,7 +1,7 @@
 export default {
   pages: [
-    'pages/index/index',
     'pages/booking/index',
+    'pages/index/index',
     'pages/test/index',
     'pages/policy/index',
     'pages/plan/index',
@@ -26,15 +26,13 @@ export default {
   tabBar: {
     custom: true,
     color: '#8a8a93',
-    selectedColor: '#ffd28a',
-    backgroundColor: '#000000',
-    borderStyle: 'black',
+    selectedColor: '#6284ff',
+    backgroundColor: '#ffffff',
+    borderStyle: 'white',
     list: [
-      { pagePath: 'pages/booking/index', text: '活动' },
+      { pagePath: 'pages/booking/index', text: '预约' },
       { pagePath: 'pages/test/index', text: '测评' },
-      { pagePath: 'pages/index/index', text: '首页' },
-      { pagePath: 'pages/content/index', text: '资讯' },
-      { pagePath: 'pages/mine/index', text: '我的' }
+      { pagePath: 'pages/park-apply/index', text: '入驻' }
     ]
   }
 };

miniprogram/src/custom-tab-bar/index.jsx

@@ -3,18 +3,16 @@ import { View, Text } from '@tarojs/components';
 import Taro from '@tarojs/taro';
 import './index.scss';
 
-/* 与 app.config.js tabBar.list 保持一致；首页(index)居中并做特殊凸起按钮 */
+/* 与 app.config.js tabBar.list 保持一致；仅 3 项：预约 / 测评 / 入驻 */
 const LIST = [
-  { pagePath: '/pages/booking/index', text: '活动', icon: 'book' },
+  { pagePath: '/pages/booking/index', text: '预约', icon: 'book' },
   { pagePath: '/pages/test/index', text: '测评', icon: 'compass' },
-  { pagePath: '/pages/index/index', text: 'OPC', icon: 'star', center: true },
-  { pagePath: '/pages/content/index', text: '资讯', icon: 'shield' },
-  { pagePath: '/pages/mine/index', text: '我的', icon: 'user' }
+  { pagePath: '/pages/park-apply/index', text: '入驻', icon: 'shield' }
 ];
 
 export default class CustomTabBar extends Component {
   state = {
-    selected: 2 // 默认首页（居中）
+    selected: 0 // 默认预约
   };
 
   switchTab = (item, index) => {

miniprogram/src/pages/index/index.jsx

@@ -25,7 +25,7 @@ export default function Index() {
         <View className="mk-cta">
           <Button className="btn btn-cta" onClick={goTab(MK_HERO.ctaPrimary.tab)}>{MK_HERO.ctaPrimary.label} →</Button>
           <Button className="btn btn-ghost" onClick={goTab(MK_HERO.ctaSecondary.tab)}>{MK_HERO.ctaSecondary.label}</Button>
-          <Button className="btn btn-ghost" onClick={() => Taro.navigateTo({ url: '/pages/park-apply/index' })}>申请入驻</Button>
+          <Button className="btn btn-ghost" onClick={() => Taro.switchTab({ url: '/pages/park-apply/index' })}>申请入驻</Button>
           <Button className="btn btn-ghost" onClick={() => Taro.navigateTo({ url: '/pages/cert-apply/index' })}>OPC认证</Button>
           <Button className="btn btn-ghost" onClick={() => Taro.navigateTo({ url: '/pages/park-transfer/index' })}>转园申请</Button>
         </View>

miniprogram/src/pages/park-apply/index.jsx

@@ -1,5 +1,6 @@
 import { View, Text, Input, Textarea, Button, Radio, RadioGroup, Checkbox, CheckboxGroup, Picker } from '@tarojs/components';
 import Taro from '@tarojs/taro';
+import { useTabIndex } from '@/utils/tab';
 import { useState, useEffect } from 'react';
 import { phoneLogin, bindPhone, isAuthed, getUser } from '@/utils/auth';
 import {
@@ -19,6 +20,7 @@ const EMPTY = () => ({
 });
 
 export default function ParkApply() {
+  useTabIndex(2);
   const [authed, setAuthed] = useState(isAuthed());
   const [gatePhone, setGatePhone] = useState('');
   const [gateCode, setGateCode] = useState('');