fix: resolve subscription UX issues and add placeholder pages

- Profile: show "未订阅" card when subscription inactive/0 days
- Profile: subscription management navigates to page instead of modal
- Subscribe-plans: data-driven plan cards with mock payment flow
- Subscribe-plans: show current subscription status at top
- Subscribe-prompt: "先使用普通模式" goes to wear-check directly
- Add help and contact placeholder pages
- Fix unbindDevice to work without explicit deviceId

miniprogram/pages/subscribe-plans/subscribe-plans.js

@@ -1,14 +1,17 @@
-var http = require('../../utils/request')
+var api = require('../../utils/api')
+var config = require('../../config/env')
 
 Page({
   data: {
     statusBarHeight: 44,
     plans: [
-      { plan: 'monthly', price: '¥99', desc: '约3.3元/天' },
-      { plan: 'yearly', price: '¥899', desc: '省¥289' }
+      { key: 'monthly', name: '月卡', price: 99, priceLabel: '¥99', desc: '约3.3元/天' },
+      { key: 'yearly', name: '年卡', price: 899, priceLabel: '¥899', desc: '省¥289', tag: '推荐' }
     ],
     selected: 'yearly',
-    purchasing: false
+    purchasing: false,
+    subscription: null,
+    subRemaining: 0
   },
 
   onBack: function () {
@@ -24,15 +27,59 @@ Page({
     this.setData({ statusBarHeight: app.globalData.statusBarHeight })
   },
 
+  onShow: function () {
+    this.loadSubscription()
+  },
+
+  loadSubscription: function () {
+    var self = this
+    api.getSubscription().then(function (sub) {
+      self.setData({
+        subscription: sub,
+        subRemaining: sub.remaining_days || 0
+      })
+    }).catch(function () {})
+  },
+
   onSelect: function (e) {
     this.setData({ selected: e.currentTarget.dataset.plan })
   },
 
   onPurchase: function () {
+    var self = this
+    var selected = this.data.selected
+    var plan = null
+    for (var i = 0; i < this.data.plans.length; i++) {
+      if (this.data.plans[i].key === selected) {
+        plan = this.data.plans[i]
+        break
+      }
+    }
+    if (!plan) return
+
     wx.showModal({
-      title: '暂未开放',
-      content: '在线购买功能尚未开放，请联系管理员开通订阅。',
-      showCancel: false
+      title: '确认支付',
+      content: '模拟支付 ¥' + plan.price + '？（测试环境）',
+      success: function (res) {
+        if (res.confirm) {
+          self.doPurchase(plan)
+        }
+      }
+    })
+  },
+
+  doPurchase: function (plan) {
+    var self = this
+    self.setData({ purchasing: true })
+    api.purchase(plan.key).then(function (order) {
+      self.setData({ purchasing: false })
+      wx.showToast({ title: '支付成功', icon: 'success' })
+      setTimeout(function () {
+        wx.redirectTo({ url: '/pages/subscribe-success/subscribe-success?plan=' + plan.key })
+      }, 1000)
+    }).catch(function (err) {
+      self.setData({ purchasing: false })
+      wx.showToast({ title: err.message || '支付失败', icon: 'none' })
     })
   }
 })

miniprogram/pages/subscribe-plans/subscribe-plans.wxml

@@ -6,6 +6,18 @@
   </view>
 
   <view class="page-content">
+    <!-- Current subscription status -->
+    <view class="current-sub" wx:if="{{subscription && subscription.status === 'active' && subRemaining > 0}}">
+      <view class="current-sub-row">
+        <text class="current-sub-label">当前套餐</text>
+        <text class="current-sub-value">{{subscription.plan === 'trial' ? '试用' : subscription.plan === 'monthly' ? '月卡' : subscription.plan === 'yearly' ? '年卡' : subscription.plan}}</text>
+      </view>
+      <view class="current-sub-row">
+        <text class="current-sub-label">剩余天数</text>
+        <text class="current-sub-value">{{subRemaining}}天</text>
+      </view>
+    </view>
+
     <view class="page-title">选择订阅套餐</view>
 
     <view class="service-card">
@@ -17,17 +29,11 @@
     </view>
 
     <view class="plans">
-      <view class="plan {{selected === 'monthly' ? 'selected' : ''}}" bindtap="onSelect" data-plan="monthly">
-        <view class="plan-price">¥99</view>
-        <view class="plan-name">月卡</view>
-        <view class="plan-save">约3.3元/天</view>
-      </view>
-      <view class="plan {{selected === 'yearly' ? 'selected' : ''}}" bindtap="onSelect" data-plan="yearly">
-        <view class="plan-tag" wx:if="{{selected !== 'yearly'}}">推荐</view>
-        <view class="plan-tag plan-tag-active" wx:else>推荐</view>
-        <view class="plan-price">¥899</view>
-        <view class="plan-name">年卡</view>
-        <view class="plan-save">省¥289</view>
+      <view class="plan {{selected === item.key ? 'selected' : ''}}" wx:for="{{plans}}" wx:key="key" bindtap="onSelect" data-plan="{{item.key}}">
+        <view class="plan-tag {{selected === item.key ? 'plan-tag-active' : ''}}" wx:if="{{item.tag}}">{{item.tag}}</view>
+        <view class="plan-price">{{item.priceLabel}}</view>
+        <view class="plan-name">{{item.name}}</view>
+        <view class="plan-save">{{item.desc}}</view>
       </view>
     </view>
 

miniprogram/pages/subscribe-plans/subscribe-plans.wxss

@@ -1,3 +1,29 @@
+.current-sub {
+  background: #fff9e6;
+  border: 2rpx solid #DCB982;
+  border-radius: 20rpx;
+  padding: 20rpx 24rpx;
+  margin-bottom: 24rpx;
+}
+
+.current-sub-row {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 8rpx 0;
+}
+
+.current-sub-label {
+  font-size: 24rpx;
+  color: #666666;
+}
+
+.current-sub-value {
+  font-size: 24rpx;
+  color: #333333;
+  font-weight: 600;
+}
+
 .service-card {
   display: flex;
   align-items: center;