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' })
     })
   }
 })