feat(debug): temporary BLE debug page for on-device verification

- entry in profile menu, visible only while a device is connected
- live FFE4 readout: 7x PD, VBAT, fitting, scan wave marker, run state
- tap a face-map region to fire a 2s single-region treat command
  (verifies region-to-IO mapping on the physical mask)
- wavelength selector (red/ir/uv/yellow) to verify color byte order
- scan command / full-face 2s / stop buttons, hex log of every write
- intentionally not i18n'd; remove page before release

miniprogram/pages/profile/profile.js

@@ -19,6 +19,13 @@ Page({
   onShow: function () {
     i18n.bind(this)
     this.loadProfile()
+    // 临时调试入口：仅设备已连接时显示（上线前随 ble-debug 页一并移除）
+    var ble = require('../../services/ble')
+    this.setData({ debugVisible: ble.isConnected() })
+  },
+
+  onOpenDebug: function () {
+    wx.navigateTo({ url: '/pages/ble-debug/ble-debug' })
   },
 
   onLightInfo: function () {