fix: improve UX and fix admin console display issues

Miniprogram:
- Add back buttons to all custom-nav pages
- Add debug/mock buttons (BLE connect, wear check, treatment)
  controlled by __DEV__ flag (hidden in prod)

Admin console:
- Fix log page using nonexistent fields (operator_type, target_type)
  now correctly reads admin_id/user_id/action/detail from API
- Fix subscription date fields (started_at→start_time, expired_at→expire_time)
- Wire up subscription detail/extend/renew action buttons
- Wire up device detail "查看完整日志" button
- Add "创建订阅" button to subscription toolbar
- Fix subscription status mapping (2=expired, 3=cancelled)

Docs:
- Add detailed architecture docs for server, miniprogram, admin console

miniprogram/pages/ble-connect/ble-connect.js

@@ -1,5 +1,6 @@
 var ble = require('../../services/ble')
 var http = require('../../utils/request')
+var config = require('../../config/env')
 var app = getApp()
 var SCAN_TIMEOUT = 15000
 
@@ -9,14 +10,24 @@ Page({
     deviceId: '',
     bindToken: '',
     state: 'scanning',
-    error: ''
+    error: '',
+    devMode: false
+  },
+
+  onBack: function () {
+    wx.navigateBack({
+      fail: function () {
+        wx.reLaunch({ url: '/pages/index/index' })
+      }
+    })
   },
 
   onLoad: function (options) {
     this.setData({ statusBarHeight: app.globalData.statusBarHeight })
     this.setData({
       deviceId: options.device_id || '',
-      bindToken: options.bind_token || ''
+      bindToken: options.bind_token || '',
+      devMode: config.__DEV__ || false
     })
     this.startBleConnect()
   },
@@ -83,5 +94,40 @@ Page({
   onRetry: function () {
     ble.disconnect()
     this.startBleConnect()
+  },
+
+  onMockConnect: function () {
+    var self = this
+    clearTimeout(this._scanTimer)
+    ble.stopScan()
+    self.setData({ state: 'binding' })
+    // Skip BLE bind, confirm directly with server
+    http.post('/api/v1/device/bind/confirm', {
+      device_id: self.data.deviceId,
+      bind_token: self.data.bindToken
+    }).then(function () {
+      self.setData({ state: 'done' })
+      wx.redirectTo({
+        url: '/pages/bind-success/bind-success?device_id=' + self.data.deviceId
+      })
+    }).catch(function (err) {
+      self.setData({ state: 'error', error: err.message || '模拟确认失败' })
+    })
+  },
+
+  onMockBindSuccess: function () {
+    var self = this
+    clearTimeout(this._scanTimer)
+    ble.stopScan()
+    http.post('/api/v1/device/bind/confirm', {
+      device_id: self.data.deviceId,
+      bind_token: self.data.bindToken
+    }).then(function () {
+      wx.redirectTo({
+        url: '/pages/bind-success/bind-success?device_id=' + self.data.deviceId
+      })
+    }).catch(function (err) {
+      self.setData({ state: 'error', error: err.message || '模拟确认失败' })
+    })
   }
 })