fix(mp): Phase 3 品质打磨 — Loading优化+ErrorBoundary重试上限+登录安全+输入限制

- Loading 组件区分列表底部状态（无spinner）vs 加载中状态
- ErrorBoundary 添加 MAX_RETRIES=3 限制，超出提示重启
- login 页 IS_SIMULATOR 改为 === 'develop' 精确匹配
- login 密码输入 type 改为 safe-password 防截屏
- appointment/create 备注输入添加 maxlength=200
- GuestHome "查看全部" 导航到文章列表页

apps/miniprogram/src/pages/appointment/create/index.tsx

@@ -272,6 +272,7 @@ export default function AppointmentCreate() {
               className='form-input'
               placeholder='请简要描述症状'
               value={reason}
+              maxlength={200}
               onInput={(e) => setReason(e.detail.value)}
             />
           </View>

apps/miniprogram/src/pages/index/index.tsx

@@ -130,7 +130,7 @@ function GuestHome({ modeClass }: { modeClass: string }) {
           <Text className='guest-section-title'>健康资讯</Text>
           <Text
             className='guest-section-more'
-            onClick={() => Taro.switchTab({ url: '/pages/health/index' })}
+            onClick={() => safeNavigateTo('/pages/article/index')}
           >
             查看全部 ›
           </Text>

apps/miniprogram/src/pages/login/index.tsx

@@ -6,7 +6,7 @@ import { useAuthStore } from '../../stores/auth';
 import './index.scss';
 
 const IS_DEV = process.env.NODE_ENV !== 'production';
-const IS_SIMULATOR = typeof __wxConfig !== 'undefined' && (__wxConfig as any).envVersion !== 'release';
+const IS_SIMULATOR = typeof __wxConfig !== 'undefined' && (__wxConfig as any).envVersion === 'develop';
 
 export default function Login() {
   const [username, setUsername] = useState('');
@@ -158,7 +158,7 @@ export default function Login() {
           <View className="login-field">
             <Input
               className="login-input"
-              type="text"
+              type="safe-password"
               password={!showPassword}
               placeholder="请输入密码"
               placeholderClass="login-placeholder"