feat: 微信分享钩子全页面接入 + 订阅信息结构化映射 + JWT 错误处理加强

- client: 全部页面接入 onShareAppMessage/onShareTimeline 分享钩子
- client: login 页增强、profile 订阅展示优化
- client/stores: 订阅字段扁平结构映射为 subInfo（plan/expiresAt/startDate）
- server: auth 路由 JWT 无效/过期统一返回 401 未授权响应
- server: models/tests 同步更新

client/src/pages/settings/settings.vue

@@ -1,7 +1,11 @@
 <template>
   <view class="page-settings page-layout">
     <view class="status-bar-placeholder"></view>
-    <text class="page-title">设置</text>
+    <view class="nav-bar">
+      <view class="nav-back" @click="goBack">‹</view>
+      <text class="page-title">设置</text>
+      <view class="nav-placeholder"></view>
+    </view>
 
     <!-- 偏好设置 -->
     <view class="section-title">偏好设置</view>
@@ -60,6 +64,8 @@
 </template>
 
 <script setup>
+import { onShareAppMessage, onShareTimeline } from '@dcloudio/uni-app'
+
 import { ref, onMounted } from 'vue'
 
 const pushOn = ref(true)
@@ -131,18 +137,20 @@ function showContact() {
 }
 
 function showAgreement() {
-  uni.showModal({
-    title: '用户协议 / 隐私政策',
-    content: '暂无内容',
-    showCancel: false
-  })
+  uni.navigateTo({ url: '/pages/agreement/agreement?type=terms' })
+}
+
+function goBack() {
+  uni.navigateBack()
 }
 
 // 微信小程序分享
+// #ifdef MP-WEIXIN
 onShareAppMessage(() => ({
   title: 'AI 维度 - 你的AI知识助手',
   path: '/pages/index/index'
 }))
+// #endif
 </script>
 
 <style lang="scss" scoped>
@@ -152,6 +160,24 @@ onShareAppMessage(() => ({
   background: var(--bg-primary);
 }
 
+.nav-bar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  height: 44px;
+}
+
+.nav-back {
+  font-size: 28px;
+  color: var(--text-primary);
+  padding: 0 8px;
+  line-height: 1;
+}
+
+.nav-placeholder {
+  width: 30px;
+}
+
 .status-bar-placeholder { height: 44px; }
 
 .page-title {