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/wear-check/wear-check.js

@@ -1,16 +1,26 @@
 var ble = require('../../services/ble')
+var config = require('../../config/env')
 
 Page({
   data: {
     statusBarHeight: 44,
     checking: false,
     result: null,
-    error: ''
+    error: '',
+    devMode: false
+  },
+
+  onBack: function () {
+    wx.navigateBack({
+      fail: function () {
+        wx.reLaunch({ url: '/pages/index/index' })
+      }
+    })
   },
 
   onLoad: function () {
     var app = getApp()
-    this.setData({ statusBarHeight: app.globalData.statusBarHeight })
+    this.setData({ statusBarHeight: app.globalData.statusBarHeight, devMode: config.__DEV__ || false })
   },
 
   onShow: function () {
@@ -47,5 +57,9 @@ Page({
 
   onRetry: function () {
     this.checkWearing()
+  },
+
+  onMockWearOk: function () {
+    this.setData({ checking: false, result: 'ok' })
   }
 })

miniprogram/pages/wear-check/wear-check.wxml

@@ -1,5 +1,6 @@
 <view class="page">
   <view class="page-header page-header-pink" style="padding-top: {{statusBarHeight + 24}}px;">
+    <view class="nav-back" bindtap="onBack">‹ 返回</view>
     <view class="page-header-title">确认佩戴</view>
     <view class="page-header-subtitle">请确保面罩贴合面部</view>
   </view>
@@ -39,5 +40,10 @@
     </view>
 
     <button wx:if="{{result === 'ok'}}" class="btn-primary mt-30" bindtap="onNext">设置护理参数</button>
+
+    <view class="debug-actions" wx:if="{{devMode}}">
+      <view class="debug-label">🔧 调试工具</view>
+      <button class="btn-secondary btn-sm" bindtap="onMockWearOk">模拟佩戴确认</button>
+    </view>
   </view>
 </view>