chore: remove all mock/debug code for production release

Miniprogram:
- ENV switched to 'prod' (disables __DEV__ flag)
- Deleted mock.js and test-ble-frame.js
- Removed mockBind/mockPurchase from api.js
- Removed all debug UI panels and onMock* handlers from 6 pages
- Removed mock purchase fallback in subscribe-plans
- Removed SIMPLE PERIPHERAL dev board from BLE scan

Server:
- Removed /device/mock-bind route
- Removed /subscription/mock-purchase route
- Removed dev_openid fallback in wechat.js
- Removed mockBind() from binding.dao.js
- Removed mock fallback in purchase endpoint
- NODE_ENV default changed to 'production'

Admin:
- ENV switched to 'prod'

All mock code preserved in 'test' branch for future development use.

server/src/lib/wechat.js

@@ -51,11 +51,7 @@ async function getAccessToken() {
 }
 
 async function code2Session(code) {
-  if (config.nodeEnv === 'development' && (!code || code === 'local' || String(code).indexOf('dev_') === 0)) {
-    return { openid: 'dev_openid_' + String(code || 'local').slice(-8) }
-  }
   if (!config.wechat.appid || !config.wechat.secret) {
-    if (config.nodeEnv === 'development') return { openid: 'dev_openid_' + String(code || 'local').slice(-8) }
     throw new Error('WECHAT_APPID or WECHAT_SECRET is not configured')
   }
   const url = 'https://api.weixin.qq.com/sns/jscode2session?appid=' + encodeURIComponent(config.wechat.appid) + '&secret=' + encodeURIComponent(config.wechat.secret) + '&js_code=' + encodeURIComponent(code) + '&grant_type=authorization_code'